Welcome to Programming in Java Language

Course Description

Course using Java introducing concepts of software development, object-oriented event-driven programming, testing and debugging, simple and complex data types, language syntax and semantics. Prerequisite: None.

Student Learning Outcomes

By the end of this course, you should be able to do the following:

(1.) Demonstrate best practices for designing end-user computing interfaces.

(2.) Discuss software development methodologies.

(3.) Use a programming or a scripting language to solve a problem.

(4.) Discuss significant trends and emerging technologies and their impact on our global society.

Vocabulary Words

vary, variable, identifier, data type, data value, value, container, ASCII (American Standard Code for Information Exchange), character (char), primitive data type, non-primitive data type, object, method, class, dot access operator, new line, size, storage, precision, type casting, widening casting, narrowing casting

Objectives

Students will:

(1.) Discuss the meaning of variables in Java
(2.) Discuss the data types in Java
(3.) Discuss the rules for using identifiers.
(4.) Write Java programs that involves the use of variables and data types.

Recommended Readings

(1.) Textbook Chapter

(2.) Java Variables, Java Data Types, and Java Type Casting by W3Schools
(https://www.w3schools.com/java/java_variables.asp)

(3.) Operators by Oracle
(https://docs.oracle.com/javase/tutorial/java/nutsandbolts/index.html)

(4.) Conversions and Contexts by Oracle
(https://docs.oracle.com/javase/specs/jls/se10/html/jls-5.html)

(5.) Designing a Swing GUI in NetBeans IDE by Apache NetBeans
(https://netbeans.apache.org/kb/docs/java/quickstart-gui.html)

(6.) Learning Swing with the NetBeans IDE by Apache NetBeans
(https://docs.oracle.com/javase/tutorial/uiswing/learn/index.html)

Videos:
Please click the RESOURCES tab of this website
Click the LinkedIn Learning (Kent State University) link
Follow the directions to access the website.
(7.) Type Java Variables and/or Java Data Types in the search bar and view the results.

Videos and Textbooks:
Please click the RESOURCES tab of this website
Click the O'Reilly Online Learning link
Follow the directions to access the website.
(8.) Type Java Variables and/or Java Data Types in the search bar and view the results.

Required Readings

A Variable is a portion of computer memory for storing a data value.
Because a variable stores a data value, it is important to identify the type of data value it stores.
This implies that any variable is associated with a data type.
The data type describes the type of data value stored by the variable.
What type of data is being stored? Are they numeric (numbers), non-numeric (letters/characters/words), etc.?
As noted with the word: variable, any value stored by it can vary (can change).
A variable is created/declared in Java by specifying the data type associated with it and assigning it to a value.
We declare a variable this way:
datatype variable = value
The equal sign is the assignment statement.
In other words, you assign something in Java using the equal sign.
Let us review the data types in Java.

Java Data Types

Data types in Java are:
(1.) Primitive data types
(2.) Non-primitive data types.

Primitive Data Types

A primitive data type is the data type that specifies the size and type of the values of the variable.
It is predefined in the Java language. This means that it is already defined in the Java language.
It always has a value. It cannot be null.
When a primitive data type is declared, it always begins with a lowercase letter.
Primitive data types have various sizes depending on the data type. The sizes are not the same.
It cannot be used to call methods.
As of today: 09/03/2020; there are eight primitive data types in Java.
They are:

Primitive Data Type	Declaration	Size	Description
(1.) Integer (Byte)	byte	1 byte (8 bits)	Integers from -128 to 127 are stored
(2.) Integer (Short)	short	2 bytes (16 bits)	Integers from -32,768 to 32,767 are stored
(3.) Integer (Integer)	int	4 bytes (32 bits)	Integers from -2,147,483,648 to 2,147,483,647 are stored
(4.) Integer (Long)	long	8 bytes (64 bits)	Integers from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 are stored NOTE: End any integer declared with the long data type with an uppercase L
(5.) Floating Point (Float)	float	4 bytes	Up to 7 decimal places are stored. NOTE: End any decimal declared with the float data type with a lowercase f
(6.) Floating Point (Double)	double	8 bytes	Up to 15 decimal places are stored. NOTE: End any decimal declared with the double data type with a lowercase d
(7.) Boolean	boolean	1 bit 0 = false, 1 = true Make the connection with electronic devices. 0 = Off; 1 = On	Only false and true values are stored Displays as 0 and 1 respectively
(8.) Character	char	2 bytes	Only a single character/letter is stored. The decimal values of ASCII characters/values are also stored. NOTE: If you intend to use the decimal values of ASCII characters/values, you must declare it with the char data type and the decimal value should not be included in quotation marks.

Student: You have talked about size. But, you said it cannot call methods.
May you please explain?
Teacher: We shall discus it later.
Let us look at non-primitive data types.
Student: That is the issue.
I get lost when you keep going.
Is it not better to explain any concept you mention? Also give examples.
Teacher: No worries.
Let us look at the non-primitive data types.
The non-primitive data types can call methods/functions.
Then, we discuss variables.
Then, we can review some examples.
Student: Now, you mention functions
Teacher: A method is a function
There are some concepts we shall mention, but not discuss immediately.
We shall discuss those concepts in later modules.
Some of those concepts would be discussed in the next course.

Non-Primitive Data Types

A non-primitive data type is the data type that refers to objects.
Because it refers to objects, it is also known as a reference type.
When a non-primitive data type is declared, it always begins with an uppercase letter.
Non-primitive data types have the same size.
They are used to call methods.
Besides the String data type, all other non-primitive data types are not predefined in the Java language. They are defined by the programmer. This implies that the String data type is the only non-primitive data type that is predefined in the Java language.
Non-primitive data types may or may not have a value. They can be null.
Examples of non-primitive data types are: Strings, Arrays, Classes, and Interface among others.

Let us review the variables in Java.

Java Variables

Java variables are identified with unique names known as idenfiers.
It is important to use identifiers that are meaningful and descriptive.
Anyone reviewing your program should not have to guess the meaning of your variable.

As you can see (based on the image below: Variables, Data Types, Values:)
The variables I used in that example are meaningful and descriptive
Those variables are:
state to denote the State of Ohio, OH
numState to denote the number of the State of Ohio in an alphabetical listing of the state names
povertyRate to denote the poverty rate of Ohions according to the $2000$ census data
landArea to denote the land area of the Ohio according to the $2000$ census data
motto to denote the motto and seal of the Great State of Ohio
ismottoTrue to denote the Boolean data type if the motto is true
Even without the comments, you already have an idea of the meaning of my variables.
I should not have to guess the meaning of your variables.

Naming Variables

Variable names:
(1.) Can be single letters (please avoid unless if used in loops)

(2.) Can contain a combination of letters, digits, and underscores but must not begin with a number.
It may begin with a letter or an underscore.
(a.) Please avoid underscores
Avoid underscores even if the variable name does not begin with an underscore.
(b.) Use a combination of letters and digits such as:
num1 to represent the first number
variable1 to represent the first number

(3.) Can contain only letters but must not be any of the reserved keywords.
The reserved keywords that are still in use are:
abstract, assert, boolean, break, byte, case, catch, char, class, continue, default, do, double, else, enum, extends, final, finally, float, for, if, implements, import, int, interface, long, native, new, package, private, protected, public, return, short, static, strictfp, super, switch, synchronized, this, throw, throws, transient, try, void, volatile, while
The reserved keywords that are not in use are:
const, goto
The const keyword is replaced with the final keyword.
NOTE: You cannot use any of the reserved keywords as an identifier/variable name regardless of whether they are in use or not in use.

(a.) The letters can be Camel case (similar to the hump of a camel) such as:
firstVariable...the V is the hump
In Camel casing letters: two letters are merged as one; the first letter of the second word is an uppercase letter while all other letters are lower case letters.
In firstVariable, V is uppercase; all other letters are lower case
(b.) The letters can be Pascal case such as FirstVariable
In Pascal casing, two letters are merged as one; the first letter of the first word and the first letter of the second word are uppercase letters while all other letters are lower case letters.
In FirstVariable, F and V are uppercase; all other letters are lowercase.
(c.) uppercase letters (please avoid...it denotes someone who is yelling)
(d.) lowercase letters (okay, but try to avoid)

Student: What if you have three words?
How do you write it in Camel case? Pascal case?
Teacher: Say we want to write the variable, first arithmetic sequence
Camel case: firstArithmeticSequence...A and S are the only uppercase
Pascal case: FirstArithmeticSequence...F, A, S are the only uppercase

In this course, for all applicable variables; please use:
(i.) A combination of letters and digits such as num1 OR
(ii.) Camel case letters such as firstNumber OR
(iii.) Pascal case letters such as FirstNumber
***We shall use single characters when we write conditions for Iteration statements/Loops because it is easier to use single characters in such cases. We shall see examples when we discuss loops. However, feel free not to use it if you wish.***

(4.) Can contain only letters but must not be these literals: true, false, null

(5.) Cannot contain whitespaces or special characters.
The special characters are all the non-numeric and non-alphabet characters on your keyboard such as ~ (tilde), !(exclamation), @ (asperand), # (hash), $ (dollar), % (percent), ^ (caret), & (ampersand), * (asterisk).
A whitespace is a horizontal or vertical space.
For example: myNum has no whitespace; but my Num has a whitespace.
Variable names cannot contain whitespaces.
Hence: myNum is acceptable, but my Num is not acceptable.

Declaring Read-Only Variables: Use the final keyword (constant keyword)
As we have learned, a variable vary. The value changes.
However, read-only variables do not change.
Sometimes, we need these kind of variables.
We have to create/declare them using the final keyword.
For example, if we want to use the approximate value of pi as $3.142$ rather than using the exact value, we can declare it as:
final int $piValue = 3.142$
This means that the variable, piValue is a read-only variable
It will not change it's value.

Student: May you please give code examples?
Teacher: Sure.
Let us review these two examples.

We shall create a new project, Module 2
So, we have two projects: Module 1 and Module 2
Before you run Module2.java, you will need to:
(1.) Close Module1.java from the code window.
(2.) Open only Module2.java in the code window.
(3.) Click the Run menu tab. Then, click Clean and Build Project (Module 2)
Do these steps whenever you create and want to run a new project without deleting any previous projects.




As you can see, the variable piValue2 cannot be changed because it was declared as a read-only variable (using the final keyword)



Teacher: As you see: for the new value of piValue1, we can modify the value of any variable we create, by specifying another value for that same variable name.
Student: But, why do we need to do this?
Can't we just create another variable with that second value?
Teacher: Good point.
Yes, it is much better to create another variable with the new value.
However, when we work with statements and sorting techniques among others; it may be more efficient to just assign the new value to the same variable; rather than create another variable and assign the new value to it.
For example: if you are sorting through a loop also known as an iteration statement; we can create a variable, and write a conditional statement that when you compare an element in the array with the next element; assign the value of the greater element to the variable.
Rather than create a new variable, assign any greater value to the variable as you compare elements in the array.
There are some terms I just used, that we shall discuss in later modules.

(6.) Are case sensitive.
These are all different variables:
firstresult (lowercase), firstResult (Camel case), FirstResult (Pascal case), Firstresult, FIRSTRESULT (uppercase), first_result (snake case)

Let us review more variable examples in Java
A variable can store the number, say 5 in a line of code; and the same variable can store a different number, say 7 in another line of code.
So, the values stored by a variable can change.

An example with integers:



An example with strings:



Teacher: Back to your question regarding a method
Did you notice we used the println() method and the lineSeparator() method? We used the System class to call those methods using the dot access operator.
The period punctuation mark is known as the dot access operator.
Student: So, the method belongs to that class?
Teacher: That is correct.
Hence we were able to call it.
Student: So, what is a class? Also, you mentioned object initially?
Teacher: We create a class in Java.
When we want to use that class, we have to call it.
Calling that class means creating an object.
We shall discuss these terms later.
Student: So, what you are saying is that primitive data types cannot call a method, but non-primitive data types can?
Teacher: That is correct.
Student: May you show me an example?
Teacher: Please wait. When we discuss Strings, we shall review examples.

Variables, Data Types, Values:

Type Casting

Type Casting is the conversion of a value from one primitive data type to another primitive data type.
Type casting in Java can be:
(1.) Widening Casting is the conversion of a value from a smaller primitive data type to a larger primitive data type.

                    byte to short
                    byte to char
                    byte to int
                    byte to long
                    byte to float
                    byte to double 
                    short to char
                    short to int
                    short to long
                    short to float
                    short to double
                    char to int
                    char to long
                    char to float
                    char to double 
                    int to long
                    int to float
                    int to double
                    long to float
                    long to double
                    float to double
                    

This is done automatically.

(2.) Narrowing Casting is the conversion of a value from a larger primitive data type to a smaller primitive data type.

                    double to float
                    double to long
                    double to int
                    double to char
                    double to short
                    double to byte
                    float to long
                    float to int
                    float to char
                    float to short
                    float to byte
                    long to int
                    long to char
                    long to short
                    long to byte
                    int to char
                    int to short
                    int to byte
                    char to short
                    char to byte
                    short to byte
                    

This is done manually.
Please review the screenshots.
Review the comments.

Let us demonstrate some examples of Widening Casting and Narrowing Casting.
We shall also confirm the output size.

Widening Casting
Conversion from Integer data type to Double data type


Narrowing Casting
Conversion from Double data type to Integer data type

GUI Programming: Electronic Flashcards with Java

As usual, we shall develop desktop applications that involves the use of variables and data types.
Let us develop desktop applications for the console application we did for the State of Ohio
We shall use several toolboxes (Palette tools).
Remember that the Midterm Project is a desktop application.
Hence, it is necessary to start getting familiar with GUI programming.
Please review the desktop application we did in Module $1$ to understand the basic steps.
We shall give appropriate names for our projects.

First Flashcard: Variables and Data Types: Labels and Buttons

Design User Interface and Set Properties

JFrame Form: Adjust and Align
title property: State of Ohio: Labels and Buttons

Palette (Toolbox)

Palette	Property
Panel Adjust and Align to cover entire JFrame Form	background: RGB → Color Code: F5DEB3 (This is for the color: Wheat) font: Font: Times New Roman;     Font Style: Plain;     Size: 24 Change Variable Name: ohioPanel
Label 1 (LHS): Adjust and Align	text: State font: Font: Times New Roman;     Font Style: Plain;     Size: 24
Label 2 (RHS): Adjust and Align	border: Etched Border Please see image below the table for illustration (Setting the border should be done first) Adjust and Align again font: Font: Times New Roman;     Font Style: Plain;     Size: 24 Change Variable Name: stateLabel
Right-click the State label and Duplicate Please see image below the table for illustration	text: Number
Right-click the Label 2 and Duplicate Please see image below the table for illustration	Change Variable Name: numberLabel Adjust and Align the Number text label to be in line with the numberLabel name label
Select both the Number text label and numberLabel name label by: Clicking on them, holding the CTRL key on your keyboard, and clicking on the other one. How do you know if it was done well? The Properties Area indicates Multiple Objects. Right-click Duplicate Both labels are duplicated. Please see image below the table for illustration Click on each label and make changes as noted below. Adjust size and Align as necessary. Do this for the rest of the labels.
Duplicate Label	text: Poverty Rate Change Variable Name: povertyRateLabel
Duplicate Label	text: Land Area Change Variable Name: landAreaLabel
Duplicate Label	text: Motto Change Variable Name: mottoLabel
Duplicate Label	text: Is Motto true? Change Variable Name: booleanLabel
Button	text: State of Ohio font: Font: Times New Roman;     Font Style: Plain;     Size: 24 background: RGB → Color Code: FFFFFF (This is for the color: White) Change Variable Name: ohioButton
Duplicate Button	text: Clear Change Variable Name: clearButton
Duplicate Button	text: Exit Change Variable Name: exitButton

Set the border of the RHS Labels


Duplicate Labels



Duplicate both Labels at the Same Time


We discussed the other tasks in Module 1.

Code our Program (Write the Program Code)

(1.) Run the program and select OhioFlashcard1 as the main class.
Close the application and let us code the program.

(2.) In the Design Area, double-click the State of Ohio button.
This leads to the Source Area
Scroll all the way to the top and begin to ...

(3.) Write the code.
Please review the screenshots.
Review the comments.

Design Area


Program Code







Run the Program

In the previous application, I closed the Palette (Toolbox) Area and the Properties Area so I can have more space for the interface.
I used a laptop and I needed more space in the Design Area
To view the Palette and the Properties Area, please click: $Window \rightarrow IDE\;\;Tools \rightarrow Palette$ and $Window \rightarrow IDE\;\;Tools \rightarrow Properties$
It is also shown in the screenshots below.

Second Flashcard: Variables and Data Types: Text Area and Buttons

Please review the previous GUI applications.

Design User Interface and Set Properties

JFrame Form: Adjust and Align
title property: State of Ohio: Text Area and Buttons

Palette (Toolbox Controls)

Palette	Property
Panel Adjust and Align to cover entire JFrame Form	background: RGB → Color Code: FFF8DC (This is for the color: Cornsilk) font: Font: Times New Roman;     Font Style: Plain;     Size: 24 Change Variable Name: ohioPanel
Text Area: Adjust and Align	font: Font: Times New Roman;     Font Style: Plain;     Size: 24 Change Variable Name: ohioTextArea
Button: Adjust and Align	text: State of Ohio font: Font: Times New Roman;     Font Style: Plain;     Size: 24 background: RGB → Color Code: FFFFFF (This is for the color: White) Change Variable Name: ohioButton
Duplicate Button: Adjust and Align	text: Clear Change Variable Name: clearButton
Duplicate Button: Adjust and Align	text: Exit Change Variable Name: exitButton

Code our Program (Write the Program Code)

(1.) Run the code and select OhioFlashcard2 as the main class.
Close the application and let us code the program.

(2.) In the Design Area, double-click the State of Ohio button.
This leads to the Source Area
Scroll all the way to the top and begin to...

(3.) Write the code.
Please review the screenshots.
Review the comments.

Design Area


Program Code






Run the Program




We shall explore more Palette tools (toolbox controls) in subsequent modules.

Some Substantive Posts

(1.) Using at least five complete sentences and at least five different variables and data types, write a program of the summary of what you learned in this module.

(2.) Write a program of a short story, a poem, or drama using at least five sentences and at least five different variables and data types.

(3.) Write a program that displays examples of all the Primitive data types and the String data type.

(4.) Write a program that demonstrates at least ten examples of Widening Type Conversions
Use the data types listed in this Module.

(5.) Write a program that demonstrates at least ten examples of Narrowing Type Conversions
Use the data types listed in this Module.

(6.) Write a program of a short story, a poem, or drama using at least five sentences, the same variable, and at least three different data types.

For Question (7.)
Please review: Conversions and Contexts
(https://docs.oracle.com/javase/specs/jls/se10/html/jls-5.html) for the other conversions.

Specific type conversions in the Java programming language are divided into 13 categories.
(I.) Identity Conversion
(II.) Widening Primitive Conversion
(III.) Narrowing Primitive Conversion
(IV.) Widening and Narrowing Primitive Conversion
(V.) Widening Reference Conversion
(VI.) Narrowing Reference Conversion
(VII.) Boxing Conversion
(VIII.) Unboxing Conversion
(IX.) Unchecked Conversion
(X.) Capture Conversion
(XI.) String Conversion
(XII.) Forbidden Conversions
(XIII.) Value set Conversion

(7.) Using at least five complete sentences and at least five different variables and data types, discuss any of the conversions that we did not discuss in this module.

(8.) We have discussed several ways of displaying the output in a new line.
Please review all the comments in the screenshots.
Do you know of any other way/ways we can display the output in a new line besides what we discussed?
What are those ways?
Write them. Run your code and display the output.

(9.) We have discussed at least two ways of printing a decimal with a % (as seen in the povertyRate variable).
Please review all the comments in the screenshots.
Do you know of any other way/ways we can print a decimal with the percent sign besides what we discussed?
What are those ways?
Write them. Run your code and display the output.

Textbook Questions
(10.) Question $4$ on Page $106$

(11.) Question $6$ on Page $106$

(12.) Question $8$ on Page $106$

(13.) Question $10$ on Page $107$

Some Substantive Responses

(1.) Provide any of these details if they are lacking in any DB post:
Well-written comments; another approach/method to solving the question; any additional relevant details; etc.

(2.) Review the post (Discuss Questions and Assess Questions) done by your colleagues.
If your colleague developed a console application for a program, develop a desktop application for the same program.
If your colleague developed a desktop application for a program, develop a console application for the same program.

(3.) Other substantive responses.

Check Your Understanding

(1.) Develop a Graphical User Interface (GUI) of a short story, a poem, or drama using at least five sentences and at least five different variables and data types.
At least three buttons: the button that displays the information, the Clear button and the Exit button should be included.

(2.) Develop a Graphical User Interface of a short story, a poem, or drama using at least five sentences, the same variable, and at least three different data types.
At least three buttons: the button that displays the information, the Clear button and the Exit button should be included.

(3.) Develop a GUI flashcard of all the Primitive data types and the String data type.
A brief definition of each data type should be displayed when the user performs an event (such as pointing the mouse or clicking) on each data type.
Use whatever palette (toolbox controls) you prefer.

Vocabulary Words

operator, operation, operand, operator precedence, assignment operator, arithmetic operators, addition operator, subtraction operator, division operator, remainder operator, modulo operator, compound assignment operators, unary operators, unary plus operator, unary minus operator, increment operator, decrement operator, increase, decrease, logical complement, logical operators, bitwise and bit shift operators, conditional ternary operator (ternary operator), equality and relational operators, comparison operators, conditional operators, format specifier, input-output feature,

Objectives

Students will:

(1.) Discuss the operators in Java
(2.) Perform operations on variables/values
(3.) Write Java programs involving the use of operators.

Recommended Readings

(1.) Textbook Chapter

(2.)
(A.) Operators by Oracle
(B.) Summary of Operators by Orcale
(C.) Questions, Exercises, and Answers by Oracle

(3.) Java Operators and Java Math by W3Schools

(4.) (A.) Java User Input by W3Schools

Videos:
Please click the RESOURCES tab of this website
Click the LinkedIn Learning (Kent State University) link
Follow the directions to access the website.
(5.) Type Java Numbers and/or Java Operators in the search bar and view the results.

Videos and Textbooks:
Please click the RESOURCES tab of this website
Click the O'Reilly Online Learning link
Follow the directions to access the website.
(6.) Type Java Numbers and/or Java Operators in the search bar and view the results.

Required Readings

Operators

Operators are special symbols that perform specific operations on one or more operands, and returns an output.
An Operand is the variable/value on which an operation is done.

Java Operators

Operators	Symbols	Description	Code Examples
Assignment	$=$	Equal sign	int num1 = 7; System.out.println(num1); // 7
Arithmetic Addition Subtraction Multiplication Division Remainder (Modulo)	$+$ $-$ $*$ $/$ $\%$	Add Subtract Multiply Divide Remainder after a division	int num1 = 6, num2 = 2; System.out.println(num1 + num2); // 8 System.out.println(num1 - num2); // 4 System.out.println(num1 * num2); // 10 System.out.println(num1 / num2); // 3 System.out.println(num1 % num2); // 1
Compound Assignment Plus equal Subtract equal Multiply equal Divide equal Modulo equal	$+=$ $-=$ $*=$ $/=$ $\%=$	Add, then equal to Subtract, then equal to Multiply, then equal to Divide, then equal to Remainder after division, then equal to	int num1 = 5; System.out.println(num1 += 7); // 12 This means that num1 = num1 + 7; implies that num1 = 5 + 7 = 12 System.out.println(num1 -= 7); // -2 This means that num1 = num1 - 7; implies that num1 = 5 - 7 = -2 System.out.println(num1 *= 7); // 35 This means that num1 = num1 * 7; implies that num1 = 5 * 7 = 35 System.out.println(num1 /= 5); // 1 This means that num1 = num1 / 7; implies that num1 = 5 / 5 = 1 System.out.println(num1 %= 7); // 5 This means that num1 = num1 % 7; implies that num1 = 5 % 7 = 5
Unary Unary plus Unary minus Increment Decrement Logical complement	$+$ $-$ $++$ $--$ $!$	The unary operators require only one operand. Unary plus operator example $+=1$ means Increase by one Unary minus operator example $-=2$ means Decrease by two The increment, ++ and decrement, -- operators can be: prefix or postfix (suffix) Prefix Increment (evaluate the value, after it is increased) Postfix (Suffix) Increment (evaluate the value, before it is increased) Prefix Decrement (evaluate the value, after it is decreased) Suffix Decrement (evaluate the value, before it is decreased) Logical complement operator inverts(negates) the value of a boolean	int num1 = 9; System.out.println(num1+=1); // 10 System.out.println(num1-=2); // 7 System.out.println(++num1); // 10 System.out.println(num1++); // 10 System.out.println(--num1); // 9 System.out.println(num1--); // 9 // Logical Complement boolean likeSamDom = true; System.out.println(!likeSamDom); // false boolean likeSamDom = false; System.out.println(!likeSamDom); // true
Conditional Ternary	$?$	The Conditional ternary operator evaluates an expression amidst two results. If the expression is true, it returns the first result. If the expression is false, it returns the second result. The two results are separated by a colon : The expression is separated by the two results using the conditional tenary operator (question mark) ? The syntax is: expression ? result1 : result2	int num1 = 5, num2 = 2; num1 == num2 ? 1 : 0 // 0 // Is 5 equal to 2? If yes, return 1; if no, return 0 5 is not equal to 2, so 0 is returned
Equality and Relational Equal to Not equal to Greater than Less than Greater than or equal to Less than or equal to	$==$ $!=$ $\gt$ $\lt$ $\ge$ $\le$	Equality and Relational Operators are used to compare two expressions. The result is a Boolean (either true or false)	int num1 = 5, num2 = 2; (num1 == num2) // false (num1 != num2) // true (num1 > num2) // true (num1 < num2) // false (num1 ≥ num2) // true (num1 ≤ num2) // false

Please review the rest of the Operators

Let us review more examples of Arithmetic Operators and Math Functions.

A Simple Arithmetic Operation of Two Integers:



Teacher: Did you notice the quotient?
Student: Yes, Sir. I did.
That result is incorrect.
Teacher: Yes, it is.
Any suggestions?
Student: I think it is because it was declared as an integer.
Teacher: Correct.
How do we fix it?
Student: Declare it as a float?
Teacher: Let's see



Teacher: We ran into another problem.
Student: What problem?
Are those answers not correct?
Teacher: They are correct.
However, the sum, difference, and product are not really floats.
They are integers.
Student: Does it really matter?
$12.0$ is the same thing as $12$
Teacher: But, we want to display it as an integer.
What should we do?
Student I have no idea.
Teacher: We discussed it in last module.
Student Wait...let me check
Type casting?
Teacher: What type?
Student: Narrowing Casting
Teacher: Because?
Student: We want to convert from a larger type (float) to a smaller type (integer)
Teacher: That is correct.
Let's do it.



Student: That fixed it.
Teacher: It did.
But, not really.
Student: What do you mean by "not really", Sir?
Teacher: The floating type.
The precision of the floating data type...
is less than that of the double data type
Teacher: What if I do not want you to round?
Or what if I want more precision?
What should we do?
Student: Use the double data type?
Teacher: That is correct.
Let's do it.



Teacher: Is that not better?...in terms of
better precision...greater number of decimal places?
Student: But, would you require our answers like this?
How do we know what format the output will be?
Student: Would you take off points for something as minor as $12.0$ rather than $12$?
Teacher: Here is my advice.
If you know the answer of the output, then declare the input variables with the appropriate data type.
For example: we know the sum is $12$.
So, if we were to find only the sum, we would just declare both num1 and num2 as integers because the output will give us an integer.
However, if we do not know the format of the output:
Begin with the double data type because it has more precision.
If your output turns out to be an integer, narrow cast that double data type to an integer
If the output is an integer, but your output is a float or double; I shall deduct points.
One of the nice things about the NetBeans IDE is that it will help you with the type casting.
If you see a red line and you point your mouse at it, it will ask you to press the Alt and Enter key to show hints. When you do that, one of the hints will be to type cast/do the conversion. Click it and the IDE will do it for you.
We have reasons for rounding numbers. We also have reasons for not rounding numbers.
Let us solve more questions.

NOTE:
Jave recommends that we should never use the float or double data type for precise values, such as currency. (https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html)
It recommends that we use the java.math.BigDecimal class instead.
When we begin our study of classes (in the next course), we can review that class and other APIs (Application Programming Interface).
For this course, we shall use the double data type.

Let us review more examples.

Please visit my website on Numbers
(www.numbersandnotations.appspot.com/numbers.html)
Let us solve Question $10$ on that website

First Approach


We used the Java Math Functions in this approach.

Please see the complete list of the Java Math Functions
(https://docs.oracle.com/cd/E17904_01/apirefs.1111/e12048/functmath.htm#CQLLR412)

Second Approach


Let us review a case where the answer needs to be rounded.
Please visit my website on Percent Applications
(www.fractions-decimals-percents.appspot.com/percentApplications.html)
Let us solve Question $1$ on that website

We can round any value to any number of decimal places in Java.
Let us discuss at least two ways we can do it.
Both approaches involves String variables.

(1.) Importing the Java class: import java.text.DecimalFormat;
I listed this approach first because it is popular with programmers.
I prefer the third approach, but you can use whatever you prefer.

(2.) Using the String.format() method.

(3.) Using the Print Formatted method System.out.printf() method.
This is my preference.

To see the examples where I used this approach, please view the screenshots of Piecewise Functions in Module $5$.
For example:
System.out.printf("$%.2f\n", costOrder);
$ puts the dollar sign
%.2f rounds the value to two floats (two decimal places)
\n inserts a new line

Please review the screenshots and the comments for explanations.



We can solve the same question using only one variable.
In this case, we have to use Compound Assignment Operators
Question $1$ on Percent Applications
Using Compound Assignment Operators:



Please review the screenshots and the comments for explanations.






Student: Mr. C, I do not want to be confused by what you do.
Teacher: What is it my dear?
Student: You did not put d in the previous examples.
Then, you put d in this example.
That is confusing...you do something for one and you do another thing for another.
Teacher: I understand.
It is recommended that you put d when you declare a double data type for a variable
However, by default; any decimal in Java is seen as a double data type.
That is also another reason to use the double data type rather than the float data type.
The first reason is because of the precision.
Another reason is that any decimal number in Java is a double data type by default.
So, if we forget to include the d after the decimal, that is not a problem.
It is better to include it.
But, it is not a problem if you forget to include it.
Student: Okay.
What if I write: final float salesTax = 0.12
Will it work?
Teacher: No, it will not work because the decimal number is a double data type in Java by default.
If you want to use a float for that, you will need to include the f after the decimal number
Like final float salesTax = 0.12f will work as a float.
However, keep in mind that the rest of the variables will have to be floats as well. Otherwise you will have to convert them to floats.
It is much better to use the double data type.
Nice observation!

In the formatted methods (String.format() and prinf()) that we used: the format specifiers:
For example in:
System.out.printf("$%.2f\n", costOrder);
$ puts the dollar sign
%.2f rounds the value to two floats (two decimal places)
\n inserts a new line

Input/Output Feature

One of the nice features of the Java langauge is the Input/Output feature.
This feature is interactive.
You use this input/output feature in several applications.
A common application is an application that verifies one's identity by inputting the first name, last name, date of birth, etc.
To use the Input/Output feature, the Scanner is used.
In other words: write import java.util.Scanner; directly under the package.
This means that you want to: Import the Scanner class of the java.util package
Let us demonstrate the input/output feature with numbers so we see how it works.
Please review the screenshots and the comments.

Java Input/Output Feature for Arithmetic Operations and Math Functions.





Let us do another example.
Input/Output Feature: Example $2$
Let us do a real-world application for this example.
Onto the ...

Application: BMI (Body Mass Index)

Please review the BMI information on these two government websites [from the Center for Disease Control and Prevention (CDC) and the National Heart, Lung, and Blood Institute of the National Institutes of Health (NIH)]
About Adult BMI | Healthy Weight, Nutrition, and Physical Activity | CDC and
Calculate Your BMI - Standard BMI Calculator

As at today, the 3rd day of September, 2020; the BMI information on both websites are:

NIH website
Calculate Your BMI - Standard BMI Calculator


CDC website
About Adult BMI | Healthy Weight, Nutrition, and Physical Activity | CDC

Formula for Calculating Body Mass Index: United States System (Customary System)

$ BMI = \left(\dfrac{weight}{height * height}\right) * 703 \\[5ex] weight\:\:is\:\:in\:\:pounds (lb) \\[3ex] height\:\:is\:\:in\:\:inches (in) $

Formula for Calculating Body Mass Index: International System (Metric System)

$ BMI = \left(\dfrac{weight}{height * height}\right) \\[5ex] weight\:\:is\:\:in\:\:kilograms (kg) \\[3ex] height\:\:is\:\:in\:\:meters (m) \\[3ex] $ If you need help with conversion of units, please review the Tables and Examples in Measurements and Units

Teacher: What do you notice in both websites?
Student: They both have the information on the BMI.
In addition, the CDC website has information for both Adult BMI and Child & Teen BMI among others.
The NIH website has recommendations among others.
Teacher: That is correct. What else?
Student: They have the BMI calculator.
Teacher: Did you notice any difference in the calculator on both websites?
Student: The NIH website has BMI calculator for both Standard and Metric versions.
The CDC website has the BMI calculator for only the Metric version.
Teacher: Did you notice any issue/concern about the BMI information?
Student: Not really. Why?
Teacher: So, this is what we are going to do.
We are going to develop the BMI calculator.
That calculator will calculate the BMI.
Then, we shall interpret that BMI, and make a recommendation.
. The CDC website gave us the formula for calculating the BMI. So, we shall use it.
As you can see, our calculator would have to use conditional statements for the interpretation and recommendation.
But, here is the issue.
Student: Wait, I think I see the issue.
The issue is with the domains.
Teacher: Correct!
Anyone having a BMI between $18.5$ and $24.9$ both endpoints included has a Normal weight.
This is: Normal weight: [18.5, 24.9]. It is a closed interval (relate with Mathematics).
So, the Overweight range for the BMI should be the weight greater than $24.9$, (rather than beginning from $25$) and ending at $29.9$
For the Overweight range, the first endpoint is not included, but the second endpoint is included.
This is: Overweight: (24.9, 29.9]. It is a half-open half-closed interval (relate with Mathematics)
Teacher: Do you know why this would be a problem if the programmer does not fix these issues before developing the calculator?
Student: Yes. Because there would not be any interpretation for anyone whose BMI is between $24.9$ and $25$
But, I do see that the BMI information is for values rounded to one decimal place.
Teacher: That is correct.
And we shall develop our calculator to round to one decimal place.
But, it is important we fix the issues.
What if we do not want to round?
Look at the two examples on the CDC website. The BMI values were rounded to two decimal places.
If we developed our calculator to round to two decimal places with the information on those websites "as is"; then we would not have the interpretation and recommendation for those two examples ($24.98$ and $24.96$) because those values are greater than $24.9$ but less than $25$.
Student: That makes sense.
So, the last one: Obese should be BMI greater than $29.9$, rather than greater than $30$?
Teacher: That is correct.

We are going to apply what we learned so far.
We shall develop a console application and a desktop application for the Body Mass Index (BMI) calculator.
I do the console application.
You do the desktop application.
We are yet to cover Statements (covered in Module $5$). However, do not worry.
I explained my comments very well. You will understand the comments.
Please ask questions if you do not understand any of the comments.
We shall use part of Module $5$ (Decision-making statements) in the program.
Please review the screenshots and the comments.

(1.) The program should accept user inputs of:
(I.) First name
(II.) Last name
(III.) Weight
(IV. Height

(2.) The program should output the:
(A.) BMI value
(B.) Interpretation
(C.) Recommendation

(3.) The program should address user-input errors of non-positive numbers for the weight and the height.
Inform the user.
Then, exit the program. Do not allow the program to continue.
To exit the program, we use the command: System.exit(0)

And in Java is represented by the double ampersand symbol &&
Or in Java is represented by the double pipe symbol ||

Code:

Results:

Student: I have several questions, Mr. C
Teacher: Please go ahead
Student: First Question: Why did you initialize those variables?
The interpretBMI and the adviceBMI...you initialized them to empty quotation marks: ""
Teacher: Good question.
Assume we did not initialize them
We only defined them within the block of code: the If Statement
Then, we want to print them/output them outside the block of code
The program "will not be happy"
Compare it to this scenario.
A student registered to attend a school.
We did not register the front office registration desk.
But we sent the student to a classroom and the classroom teacher registered that student.
The parents come, looking for their child.
Where will the parent go first?
Student: At the front desk of course
Teacher: Good.
The front desk will first keep a record of the student before sending the student to the class.
We have to first assign the string to something before we send it to the blocks of code, and then output it.
We cannot just declare it without an assignment, then send it to a block of code to be used within that block of code only, and then want to output it outside the block of code.
Does it make sense?
Student: Yes, it does.
But what if we do not want to print the value outside the block of code?
What if we want to print the value inside each block of code where it is used?
Teacher: I am impressed by your questions.
Yes, we can do that.
But you know what that means...right?
Student: We have to write it each time for each of the conditional statement.
Teacher: That is correct.
Student: Second Question: How did you get the blue color for the heading on the console window?
Teacher: Console Log Formatting: You can find the commands on my website: American Standard Code for Information Exchange (ASCII)

GUI Programming: Develop a Standard Calculator with Java

We have done several console applications.
Now onto desktop applications.
Let us apply the knowledge we acquired in this module to develop a desktop application.
Which application comes to mind right away...a desktop application that deals with Numbers and Operators?
It's the Standard Calculator. Let's develop it. 😊
Please review the desktop applications we developed in previous modules beginning from Module $1$

Let us begin with the desktop calculator on your Windows PC/Laptop
Please see the screenshots




Let us develop the function buttons as seen in the red rectangle.

We are yet to cover Statements (covered in Module $5$). However, do not worry.
I explained my comments very well. You will understand the comments.
Please ask questions if you do not understand any of the comments.
We shall use part of Module $5$ (Decision-making statements) in the program.

First Calculator: Standard Calculator: Label, Text Field and Buttons

Design User Interface and Set Properties

JFrame Form: Adjust and Align
title property: Standard Calculator © 2021 SamDom4Peace Designs

Palette (Toolbox Controls)

Palette	Property
Panel Adjust and Align to cover entire JFrame Form	background: RGB → Color Code: FFF5EE (This is for the color: SeaShell) font: Font: Times New Roman;     Font Style: Plain;     Size: 24 Change Variable Name: calculatorPanel
Label: Adjust and Align	border: Etched Border (do this first) text: Delete jLabel1 horizontalAlignment: RIGHT (because we want to align the $0$ to the right) font: Font: Times New Roman;     Font Style: Plain;     Size: 24 border: Etched Border Change Variable Name: calculatorLabel
Text Field: Adjust and Align	text: $0$ (because we want $0$ to be the default) horizontalAlignment: RIGHT (because we want to align the $0$ to the right) font: Font: Times New Roman;     Font Style: Plain;     Size: 24 border: Etched Border Change Variable Name: calculatorTextField
Button: Adjust and Align	text: $1/x$ font: Font: Times New Roman;     Font Style: Plain;     Size: 24 background: RGB → Color Code: FFFFFF (This is for the color: White) Change Variable Name: reciprocalButton
Duplicate Button: Adjust and Align	text: $7$ Change Variable Name: sevenButton
Duplicate Button: Adjust and Align	text: $4$ Change Variable Name: fourButton
Duplicate Button: Adjust and Align	text: $1$ Change Variable Name: oneButton
Duplicate Button: Adjust and Align	text: $+/-$ Change Variable Name: plusMinusButton
Duplicate Button: Adjust and Align	text: $x^2$ Change Variable Name: squaredButton
Duplicate Button: Adjust and Align	text: $8$ Change Variable Name: eightButton
Duplicate Button: Adjust and Align	text: $5$ Change Variable Name: fiveButton
Duplicate Button: Adjust and Align	text: $2$ Change Variable Name: twoButton
Duplicate Button: Adjust and Align	text: $0$ Change Variable Name: zeroButton
Duplicate Button: Adjust and Align	text: $\sqrt{x}$ Change Variable Name: squareRootButton
Duplicate Button: Adjust and Align	text: $9$ Change Variable Name: nineButton
Duplicate Button: Adjust and Align	text: $6$ Change Variable Name: sixButton
Duplicate Button: Adjust and Align	text: $3$ Change Variable Name: threeButton
Duplicate Button: Adjust and Align	text: $.$ Change Variable Name: decimalButton
Duplicate Button: Adjust and Align	text: $\div$ Change Variable Name: divideButton
Duplicate Button: Adjust and Align	text: $\times$ Change Variable Name: multiplyButton
Duplicate Button: Adjust and Align	text: $-$ Change Variable Name: minusButton
Duplicate Button: Adjust and Align	text: $+$ Change Variable Name: plusButton
Duplicate Button: Adjust and Align	text: $=$ Change Variable Name: equalButton
Duplicate Button: Adjust and Align	text: Clear Change Variable Name: clearButton
Duplicate Button: Adjust and Align	text: Exit Change Variable Name: exitButton

Student: Mr. C, how did you get the copyright symbol in the title of the form and the square symbol, the square root symbol, and the divide symbols on the form?
Teacher: The copyright symbol is $alt + 0169$
The square symbol is $alt + 253$
The square root symbol is $alt + 251$
The division symbol is $alt + 246$
You can find these characters on my website for: American Standard Code for Information Exchange (ASCII)

Code our Program (Write the Program Code)

(1.) Run the code and select standardcalculator.StandardCalculator as the main class.
Close the application and let us code the program.

(2.) In the Design Area, double-click the $1/x$ button.
This leads to the Source Area
Scroll all the way to the top and begin to...

(3.) Write the code.
Let us use a top-down approach. So, let us write the code for each toolbox (Palette tool) in the order as seen in the Design Area.
Please review the screenshots.
Review the comments.

Design Area


Program Code




























Student: Mr. C, you used the same name variable: newNumber for different events.
Is that allowed?
Teacher: Very good observation.
We can do that because we defined that variable locally.
This means that the variable: newNumber is only recognized within that event.
If we use it outside that event, it will result in an error because we did not define it in the class.
Notice that we did not have issues with the variables we defined in the class such as firstNumber
We can use those variables anywhere within the class.

Run the Program

NaN means Not a Number It is not a real number. But it is an imaginary number. It is covered under Complex Numbers in Algebra) This calculator deals with only with real numbers.

Functionalities of the Calculator
(1.) For an operation involving two numbers: the calculator works for any two positive numbers.

(2.) For an operation involving two numbers: the calculator works if the first number is negative.

(3.) For an operation involvong one number: the calculator works for any number.

(4.) For any operation: the user sees what he/she did.

(5.) Division of a number by zero and the square root of a negative number is handled.

Limitations of the Calculator
(1.) For an operation involving two numbers: the calculator does not work for two negative numbers.

(2.) A user is able to enter two or more decimal point for the same number.

(3.) All numbers (including integers) are expressed as double data type.

The user wants $8$ to be $8$ rather than $8.0$
The user wants $8^2$ to display $64$ rather than $64.0$

(4.) The calculator computes one operation at a time.
It does not allow multiple operations simultaneously.

Second Calculator: Scientific Calculator: ComboBox, TextField, TextArea, and Buttons

Design User Interface and Set Properties

Let us design another calcuator using more toolbox controls.
For this calculator:
(1.) We want two textfields for user-input.
The two textfields will receive user-input for two numbers (the operands).
Remember that textfields accept only strings.
But we want them to accept numbers.
We shall define those numbers using the double data type (to accomodate decimals).
Then, we shall convert those numbers as strings so that the textboxes will accept them.

(2.) We want a ComboBox.
The ComboBox will contain a dropdown list of items: the operations.
We shall expand our list of operations. So, this calculator will be more of a scientific calculator.
I shall do some functions.
You do the rest of the functions (just as we did for the Standard Calculator).

(3.) We want four buttons: the Calculate, Clear Some, Clear All, and Exit buttons.

(4.) When we run our program, we want the cursor to be focused on the first textfield.
Then, we want the user to be able to use the Tab key on the keyboard to perform any operation without using a mouse.
This is an important software design concept to accommodate users with disabilities.
It is known as the Tab Order Property.
Once the user enters the first number in the first textbox; move to the ComboBox and select an operation from the dropdown list and press the Tab key; use the Tab to move to the second textbox (as applicable), enter the second number and press the Tab key (as applicable); move to the Calculate button and hit the Enter key to get the result.
The Tab Order property controls that ability for the Tab to move in that order.
We shall set the Tab Order properties of the toolbox controls accordingly.
For operations that involve two numbers such as calculating the sum, difference and the like: we want it to be: $first\;\;number \rightarrow operation \rightarrow second\;\;number \rightarrow calculate$
For operations that involve only one number such as calculating the reciprocal, square root and the like: we want to disable the second textbox so that the user would not enter a second number.

Tab Order Property

The Tab Order property determines the order in each pallete tool receives focus when the user presses the Tab key while an application is running.
The Tab Order property is zero-indexed. This means that the first one begins with a 0, the next one is a 1, the next is a 2 among others.
The Tab Order is set in the order that each pallete tool is added to the form.
It is important to run the GUI (without the code) and use the Tab key to ensure that each palette tool receives cursor focus accordingly.
If the Tab Order is not set in the way you want it, you can adjust it by moving each tool up or down.
Please review the screenshots.



Recap:
Assume the user is working with only the keyboard (software design to accommodate users who cannot use the mouse)

(1.) When the user runs the application, the cursor focus should be in the first textfield waiting for user input.
The user enters a number and presses the tab key

(2.) The next focus should be the ComboBox waiting for the user to make a selection.
The user selects an operation.
If the operation involves only one number, the second textfield is disabled so the focus moves to the Calculate button.
The command used to disable the textfield is: TextField.setEditable(false);
As you can see, to disable a TextField; the editable property of the TextField is set to the Boolean value: false
If the operation involves two numbers, the cursor focus moves to the second textfield waiting for the user to enter the second number. The user enters the second number and presses the tab key.
The next focus would be the Calculate button.
The user presses the ENTER key and the calculation is done. The result is displayed in the textarea: ResultTextArea.

(3.) The user presses the tab key and the focus should be the Clear Some button.
The user presses the ENTER key and the entries in the textfields and the textarea are cleared.

(4.) The user presses the tab key and the focus should be the Clear All button.
The user presses the ENTER key and all entries (all items in the ComboBox) are cleared.

(5.) The user presses the tab key and the focus is the Exit button.
The user presses the ENTER key and the application is closed.

Let us work on the design: the form and the palette tools.

JFrame Form: Adjust and Align
name: frame1 (by default. Leave as is)
title: Scientific Calculator © 2021 SamDom4Peace Designs (Sample)
Font: Times New Roman;    Font Style: Plain;    Size: 24
resizable: Uncheck the box
We unchecked the resizable property of the JFrame Form because we do not want the user to change the size of the application.
We want the interface to have a consistent look.

Set Properties for the Form and the Palette Tools

Palette Tools	Property
Label: Adjust and Align	text: First Number: Font: Times New Roman;    Font Style: Plain;    Size: 24
Text Field: Adjust and Align	Font: Times New Roman;    Font Style: Plain;    Size: 24 text: Delete jTextField1 horizontalAlignment: RIGHT Change Variable Name: FirstNumberTextField
Label: Duplicate the first label Adjust and Align	text: Operation:
ComboBox: Adjust and Align	Change Variable Name: OperationComboBox Font: Times New Roman;    Font Style: Plain;    Size: 24 background: RGB: Color Code Scientific Calculator: FFFFFF (means the White color) model: Delete Item 1 Item 2 Item 3 Item 4 and for teaching purposes type: Please select an operation Addition (+) [2 numbers] Subtraction (-) [2 numbers] Multiplication (*) [2 numbers] Division (÷) [2 numbers] Modulo (mod) [2 numbers] Exponent (xⁿ) [2 numbers: x is the base; n is the exponent] Log_{x}n [2 numbers: x is the base; n is the number] nth Root of x [2 numbers: x is the radicand; n is the index] Reciprocal (1/x) [1 number] Percent (%) [1 number] Absolute Value (|x|) [1 number] n! [1 number] Tangent in DEG (tan) [1 number] Sine in RAD (sin) [1 number] Cosine in GRAD (cos) [1 number]
Label: Select the first label and the first text field and Duplicate Adjust and Align	text: Second Number:
Text Field: Select the first label and the first text field and Duplicate Adjust and Align	Change Variable Name: SecondNumberTextField
Label: Duplicate the label for the Second Number: Adjust and Align	text: Result:
Text Area: Adjust and Align	Change Variable Name: ResultTextArea Font: Times New Roman;    Font Style: Plain;    Size: 24 background: RGB: Color Code Scientific Calculator: FFFFFF (means the White color) editable: Uncheck the box We unchecked the editable property of the Text Area because we do not want the user to edit the result. Further, we want the user to be able to use the Tab key and move on to the Calculate button.
Button: Adjust and Align	Change Variable Name: CalculateButton Font: Times New Roman;    Font Style: Plain;    Size: 24 background: RGB: Color Code Scientific Calculator: FFFFFF (means the White color) text: Delete jButton and write Calculate Horizontal Size: 160
Button: Copy and paste the previous button Adjust and Align	text: Clear Some Change Variable Name: ClearSomeButton Horizontal Size: 160
Button: Copy and paste the previous button Adjust and Align	text: Clear All Change Variable Name: ClearAllButton Horizontal Size: 160
Button: Copy and paste the previous button Adjust and Align	text: Exit Change Variable Name: ExitButton Horizontal Size: 160

The ComboBox

A JComboBox is a palette tool that allows the user to select items from the a list.
(https://docs.oracle.com/javase/tutorial/uiswing/components/combobox.html)
It can have two very different forms: the editable Combobox and the uneditable ComboBox.
There are several properties of the ComboBox.
We shall discuss only one property in this module: the SelectedIndex property.
The SelectedIndex property gets or sets the index of a selected item.
The ComboBox items are zero-indexed just like arrays.
This means that the first item has index: $0$, the second item has index $1$, and the third item has index $2$ among others.
The command used to specify a selected item in the ComboBox is: ComboBox.getSelectedIndex() == Index
Based on the items in the ComboBox in our program:

ComboBox Items	Index
Please select an operation	$0$
Addition (+) [2 numbers]	$1$
Subtraction (-) [2 numbers]	$2$
Multiplication (*) [2 numbers]	$3$
Division (÷) [2 numbers]	$4$
Modulo (mod) [2 numbers]	$5$
Exponent (xⁿ) [2 numbers: x is the base; n is the exponent]	$6$
$Log_{x}n$ [2 numbers: x is the base; n is the number]	$7$
nth Root of x [2 numbers: x is the radicand; n is the index]	$8$
Reciprocal (1/x) [1 number]	$9$
Percent (%) [1 number]	$10$
Absolute Value (|x|) [1 number]	$11$
n! [1 number]	$12$
Tangent in DEG (tan) [1 number]	$13$
Sine in RAD (sin) [1 number]	$14$
Cosine in GRAD (cos) [1 number]	$15$

Code our Program (Write the Program Code)

(1.) Click the Source Area.
Scroll a little bit to the top, write the comments, and begin to...

(2.) Write the code.
What should happen when the user clicks the Calculate button?
Please review the screenshots.
Review the comments.

Design Area




Program Code
To clear all the items in a ComboBox, we use the command: ComboBox.removeAllItems();





























Student: Mr. C, you used these variables: firstNumber, secondNumber, result for different events.
Is that allowed?
Teacher: Very good observation.
Yes, we can do that.
Here is the reason: we used it within each event (each conditional statement).
We defined it as a class member variable. But remember we did not specify any value for it.
Hence, we are free to use it as local variables.
We can use those variables anywhere within the class.
But you are very welcome to use different variables for the different events if you choose.

Run the Program

Some Substantive Posts

For Questions (1.) and (2.); please review the other Java operators
(https://docs.oracle.com/javase/tutorial/java/nutsandbolts/op2.html)
Using code examples and well-written comments for each operator, discuss any of these operators.

(1.) Conditional Operators

(2.) Bitwise and Bit Shift Operators

(3.) Visit my website on Numbers
(www.numbersandnotations.appspot.com/numbers.html)
Choose any applicable question and write a Java program to solve it.
Please make sure that the output of your program gives the same result as the solution of the question on my website.
You may use Arithmetic Operators, Math Functions, or both.

(4.) Visit my website on Percent Applications
(www.fractions-decimals-percents.appspot.com/percentApplications.html)
Choose any applicable question and write a Java program to solve it.
Please make sure that the output of your program gives the same result as the solution of the question on my website.
You may use Arithmetic Operators, Math Functions, or both.

(5.) Program to determine your age
***Because your age is a PII (Personal Identifiable Information), you may use a fictitious age. However, you need to test it (privately) with your actual age to make sure it works.***
Develop a Java program to determine your age based on these instructions.
ONLY one variable is required.
(Hint: If only one variable is required, this implies that you need to use Compound Assignment operators)
The user wants you to note that these instructions would only work for ages determined this year, and wants you to specify it in the program.
(a.) Pick an integer between $0$ and $10$ ($0$ and $10$ exclusive).
(b.) Multiply the integer by two.
(c.) Add five to the result.
(d.) Multiply the result by fifty.
(e.) If you already had your birthday this year, add the result to one thousand, seven hundred and seventy one. If you have not had your birthday this year, add the result to one thousand, seven hundred and seventy.
(f.) Subtract your four digit birth year from the result.
Run the code and display the output.
Explain your result.

(6.) A client wants you to develop a program to calculate the age of his child.
The instructions for the previous question still applies to this question.
However, in this case; the program will give the instructions to the child, and the child will respond.
This program is an Input/Output program.
Develop a Java program for this child.

(7.) Program to determine your date of birth.
***Because your date of birth is a PII (Personal Identifiable Information), you may use a fictitious age. However, you need to test it (privately) with your actual age to make sure it works. Develop a Java program to determine your date of birth based on these instructions.***
ONLY one variable is required.
(Hint: If only one variable is required, this implies that you need to use Compound Assignment operators).
(a.) Pick the integer that is your month of birth.
(b.) Multiply the integer by two hundred.
(c.) Add three hundred and eighty two to the result.
(d.) Divide the result by two.
(e.) Add your day of birth to the result.
(f.) Multiply the result by 100.
(g.) Add thirteen thousand, eight hundred and forty to the result.
(h.) Add the last two digits of your year of birth to the result.
(i.) Subtract thirty two thousand, nine hundred and forty from the result.
Run the code and display the output.
Explain your result.

(8.) A client wants you to develop a program to calculate the date of birth of her child.
The instructions for the previous question still applies to this question.
However, in this case; the program will give the instructions to the child, and the child will respond.
This program is an Input/Output program.
Develop a Java program for this child.

(9.) Develop a Body Mass Index (BMI) desktop application using the United States System.
Test each condition just like we did in our example for the United States System.
Address user-input errors.

(10.) Develop a Body Mass Index (BMI) console application using the International System.
The formula is on the screenshot.
Test each condition just like we did in our example for the United States System.
Address user-input errors.

(11.) Develop a Body Mass Index (BMI) desktop application using the International System.
The formula is on the screenshot.
Test each condition just like we did for the United States System.
Address user-input errors.

Questions (12.) and (13.) are meant to prepare you for the Midterm Project.
For Questions (12.) and (13.)
Develop a VB program that meets these requirements.
(I.) Consider any concept/scenario that uses conditional statements.
It will be great if you find a real-world application. However, you can make up your own.
If you decide to make up your own, please explain the scenario and the conditions well.
If you use a real-world application, please cite your source(s) accordingly. Explain the scenario and the conditions well.
Use at least two (two or more) different conditions.
The BMI Calculator has four different conditions.
But, please use any application that has at least two different conditions.
(II.) Accept user input(s).
(III.) Address user input errors.
(IV.) Test your program and display the result/output for each condition.
(V.) Test your program for user-input errors.
(VI.) Submit all the screenshots accordingly.

(12.) Develop a console application for your concept.

(13.) Develop a desktop application for your concept.

Textbook Questions
(14.) Question $12$ on Page $107$

(15.) Question $14$ on Page $107$

(16.) Question $16$ on Page $107$

Java Programming Exercises, Practice, Solution by W3Resource
Please review:
(A.) Java Math: Exercises, Practice, Solution
(B.) Java Basic Programming - Part 1: Exercises, Practice, Solution
(C.) Java Basic Programming - Part 2: Exercises, Practice, Solution
(D.) Java Data Types: Exercises, Practice, Solution
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(17.) Please focus only on Questions that deals with Numbers and Operators.
Write the Question as a comment in your program. Include the Title and the Question Number.
Write clear comments for each line of code in the Solution.
Run the program.
Submit clear screenshots.

For those who do not mind messing around with several languages at the same time
Student: Excuse me, Mr. C
This course is only for Java
What do you mean?
Teacher: You are correct.
But, these subsequent questions are not for everyone.
That is the reason I am putting them at the end.
I have a question for you.
Have you ever seen any IT/Computer Science position that requires the knowledge of only one programming language?
Student: I have not checked, Sir.
Teacher: If you intend to be in the IT/Programming field for the long run, at least four (four or more) languages are required.
If you look for IT positions at Indeed.com or other career/job websites, you will realize what I mean.
Search for java programmer, you might be surprised that even for entry level positions for a Java Programmer; they require you to have a working knowledge of several other programming languages.
Mr. C is preparing you for that...if you intend to work in the programming field for a long time.
Besides, this is a critical thinking approach.
I am required to develop and promote critical thinking questions for my students.
A programmer is basically a problem-solver irrespective of the programming language used to solve the problem.
Yes, we are working with Java. However, if you find out that C# would be better in solving a particular problem in your workplace, then you need to use C# unless your employer says otherwise.
The knowledge of several languages is a good asset. It makes you highly valuable.
Further, anyone who attempts any of the subsequent questions will still have to write the program in Java and get the same result.
The questions and solutions are in another language.
But the student will have to write the program in Java and come up with the same solution. So, we are still on track.
It is critical thinking...multiple approaches to solving a question.
Be it as it may, these subsequent questions are not required.
It is okay even if you do not look at them. 😊

C# Programming Exercises, Practice, Solution by W3Resource
Please review:
(A.) C# Basic Declarations and Expressions : Exercises, Practice, Solution
(B.) C# Basic Algorithm: Exercises, Practice, Solution
(C.) C# Data Types : Exercises, Practice, Solution
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(18.) Please focus only on Questions that deals with Numbers and Operators.
Write the Question as a comment in your program. Include the Title and the Question Number.
Write the program in Java
Run the program. Please make sure your program output is the same solution
Submit clear screenshots.

C++ Programming Exercises, Practice, Solution by W3Resource
Please review:
(A.) C++ Basic: Exercises, Practice, Solution
(B.) C++ Basic Algorithm: Exercises, Practice, Solution
(C.) C++ Math: Exercises, Practice, Solution
(D.) C++ Numbers: Exercises, Practice, Solution
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(19.) Please focus only on Questions that deals with Numbers and Operators.
Write the Question as a comment in your program. Include the Title and the Question Number.
Write the program in Java
Run the program. Please make sure your program output is the same solution
Submit clear screenshots.

Some Substantive Responses

(1.) Provide any of these if it is lacking in any DB post that solved any question in the Assess tab of this module: Well-written comments; another approach/method to solving the question; any additional relevant details; etc.

For Questions (5.) and (6.) in the Substantive Posts
Student: Mr. C, the instructions in Questions (5.) and (6.) are not correct.
The result is not my age.
How can you ask us to write a program that does not work?

(2.) Explain the result to the Student. (Answer this question only if any of your colleagues made a similar statement in the initial post.)

(3.) The Student wants only his/her age to be the result.
Without modifying any of the instructions (but using all of them) and one more instruction, extend the program to display only the Student's age.
What is the extra instruction that you would include to work for all ages? Write it. Run it. Submit clear screenshot(s).

For Questions (7.) and (8.) in the Substantive Posts
Student: Mr. C, I want the date of birth to display properly.
Teacher: Use a delimiter.
Student: What is a delimiter?
Teacher: A delimiter is a sequence of chararcters that specifies limits/boundaries of characters in a text, expression, word, etc.
A good example is the forward slash that you can use to separate that DOB in the form of: mm/dd/yyyy.
The forward slash is a delimiter.
Another example is the pipe delimiter: mm | dd | yyyy.
Another example is the hyphen delimiter: mm-dd-yyyy.
Student: Okay, how do I display the result in that format?

(4.) Explain how you would display the result for the Student.
Write the code. Run it. Submit clear screenshot(s).

(5.) Review the post (Discuss Questions and Assess Questions) done by your colleagues.
If your colleague developed a console application for a program, develop a desktop application for the same program.
If your colleague developed a desktop application for a program, develop a console application for the same program.

(6.) Other substantive responses.

Check Your Understanding

This is the NumbersOperators.jar Standard Calculator

(1.) Please review the Functionalities of the Calculator and the Limitations of the Calculator as explained in the Learn tab.
Maintain all the functionalities of the calculator.
Address the first three limitations.
You may use my code if you wish (in this case because you are extending the functionlities of my program) and/or your code.

(2.) The first standard calculator we programmed did not contain all the functions.
This is what we did.


This is what you should do.

Develop a calculator that contains all the functions.
Due the scope of this module, you may work with only the integer data type. However, your calculator should handle quotients that are decimals (division of integers that results in decimals)
Your calculator should also handle percentages (for those integers whose percentages gives decimals).
Because you are working with only integers, you may remove the decimal function button and replace it with any function you prefer.

Please note:
The C function is the Clear function. It deletes everything.
It clears the first number, operation, and the second number.

The CE function is the Clear Entries function. It deletes "some" things.
It clears only the second number. You can replace the second number and continue with the calculation.
It does not clear everything.
This is used when the entire calculation does not need to be deleted.

The BS (backspace) function (you may use alt+174 key if you prefer) is the backspace function.
It deletes part of the first number or the second number.
This is also used when the entire calculation does not need to be deleted.

Let us look at an example. You may test it.

$ \underline{Example} \\[3ex] 25 + 32 \\[3ex] \color{red}{C} \;\; deletes\;\;everything \\[3ex] \color{red}{CE} \;\; deletes\;\;only\;\;32 \\[3ex] \color{red}{BS} \;\; deletes\;\;only\;\;2 \\[3ex] $ This is the executable Numbers.jar Scientific Calculator

(3.) We developed the scientific calculator.
However, it does not contain all the functions.
Develop the scientific calculator GUI that contains all the functions.
You may extend my application by adding the missing functions if you wish, or you may develop your own with all the functions.
You may use my Code Scientific Calculator if you wish (in this case because you are extending the functionlities of my program) and/or your Code Scientific Calculator.

(4.) Develop a console application for an extension of the Body Mass Index (BMI) application example.
We did the application for the United States System (Customary System).
Extend the application by developing the calculator for the International System (Metric System).
The formula is on the screenshot.
Ask the user which system he/she wants to use to calculate the BMI.
Based on the user's selection, display the appropriate units for the weight and the height, as well as the output.
Test all the conditions for both systems.

This is the BodyMassIndexApplication.jar executable file
You may click the link to download and run it. No worries, it is safe.
It is a desktop application.
If you have Java on your computer (PC or Mac desktop/laptop), click the file and run the application directly on your desktop.

(5.) Develop a desktop application for an extension of the Body Mass Index (BMI) application example.
We did the application for the United States System (Customary System).
Extend the application by developing the calculator for the International System (Metric System).
The formula is on the screenshot.
Ask the user which system he/she wants to use to calculate the BMI.
Your desktop application should have the dropdown list for both systems, but should be null be default (using a ComboBox)
Alternatively, you may choose to use Radio Buttons.
Based on the user's selection, display the appropriate units for the weight and the height, as well as the output.
Test all the conditions for both systems.

Question (6.) is meant to prepare you for the Midterm Project.
Develop a VB program that meets these requirements.
(I.) Consider any concept/scenario that uses conditional statements.
A real-world application is required. You may not make up your own.
Please cite your source(s) accordingly. Explain the scenario and the conditions well.
Use at least two (two or more) different conditions.
The BMI Calculator has four different conditions.
But, please use any application that has at least two different conditions.
(II.) Accept user input(s).
(III.) Address user input errors.
(IV.) Test your program and display the result/output for each condition.
(V.) Test your program for user-input errors.
(VI.) Submit all the screenshots accordingly.

(6.) Develop a console application and a desktop application for your concept.

Vocabulary Words

character, string, Boolean, bool, function, argument, dot member access operator, concatenator operator, string literal, empty string, date, time

Objectives

Students will:

(1.) Discuss the Java string data type.
(2.) Discuss the Java Boolean data type.
(3.) Discuss Date and Time in Java.
(4.) Write programs that involves the String data type.
(5.) Write programs that involves the Boolean data type.
(6.) Write programs that involves Date and Time.

Recommended Readings

(1.) Textbook Chapter

(2.) Java Strings and Java Booleans
(Java Strings: www.w3schools.com/java/java_strings.asp) and (Java Booleans: www.w3schools.com/java/java_booleans.asp)

(3.) Java SE 8: Getting Started with String Processing: Invoking the String Class Methods
(Java SE 8: Getting Started with String Processing: Invoking the String Class Methods: www.oracle.com/webfolder/technetwork/tutorials/obe/java/String/String.html#section2)

Videos:
Please click the RESOURCES tab of this website
Click the LinkedIn Learning (Kent State University) link
Follow the directions to access the website.
(4.) Type Java Strings and/or Java Booleans and/or Java Date and Time in the search bar and view the results.

Videos and Textbooks:
Please click the RESOURCES tab of this website
Click the O'Reilly Online Learning link
Follow the directions to access the website.
(5.) Type Java Strings and/or Java Booleans and/or Java Date and Time in the search bar and view the results.

Required Readings

Strings

A String is a sequence of ordered characters.
It is built out of characters.
It is enclosed in matching single or double quotation marks.

Remember the first Java program we wrote, the output...the message, THANK GOD.
That is an example of a string.
Let us review more examples of what we could do with Java strings.

Join strings.
Let us discuss several ways of joining strings.
Please review the screenshots and the comments.

First Approach: Concatenator operator


Teacher: There is an issue here.
Student: There is no space between your first and last name.
Teacher: That is correct.
How do we fix it?
Student: Include a space between the names.
Teacher: There are several ways we can do this.
We can include an empty string in between the names.

Join two strings using Concatenation operator (Space included between the strings)


Teacher: We can also use the StringBuffer class with the Append method
The Append method does not automatically include a space between the strings.
So, we have to include the space appropriately.


Second Approach: StringBuffer class with the Append method


Student: In the Second Approach: StringBuffer class with the Append method
You did not use the string variables: firstName and lastName
Teacher: That is correct.
Student: What if I want to use the string variables with the append method?
Instead of using strings?
Do you understand what I mean?
Teacher: I do.
Nice question.
We can do it.
We shall have the variable: firstName as the argument of the object
We append an empty string
Then, we append the lastName.
Student: So, we can use two append methods with a string?
Teacher: Yes.
We shall use those append methods accordingly with the dot member access operator (the period, .)
Let us do this with the Third Approach.
However, you can still do it with the Second Approach.
But, let us see another approach.

Third Approach: StringBuilder class with the Append method


Student: What is the difference between the StringBuffer class and the StringBuilder class?
Which one should we use?
Teacher: Good question.
We shall discuss the differences in Advanced Java course.
But, I prefer you use the StringBuilder class because it is more efficient than the StringBuffer class.
However, it depends on what you want to do with the string.
We shall discuss the String class, the StringBuffer class, and the StringBuilder class in Advanced Java course.

Escape Sequences
An escape sequence is a character preceded by a backslash (\)

Escape Sequences

Escape Sequence	Description
\t	Insert a tab space
\b	Insert a backspace
\n	Insert a new line
\r	Insert a carriage return
\f	Insert a formfeed
\'	Insert a single quote
\"	Insert a double quote
\\	Insert a backslash

Backslash Escape Sequence, \
Sometimes, we write sentences that has the single quotation marks and the double quotation marks.
How do we display these sentences in a Java program?
We have to use the backslash escape sequence
It turns special characters into string characters.
Please review the screenshots and the comments.

Insert single quote, double quote, backslash in sentences


Teacher: I do not want to scroll all the way to the right to see the entire results.
What should I do?
Student: Insert a new line?
Teacher: That is correct....insert a new line escape sequence.
The third quote: the quote by St. Jerome is okay.
But, let us add new lines to the first quote: the quote by St. Francis of Assisi and the second quote: the quote by Maya Angelou.

Input/Output Feature with Strings

In the previous module, we reviewed some examples of the Input/Output with Numbers.
In this module, let us demonstrate the Input/Output feature with Strings.
As we did with Numbers, we have to import the Scanner class of the java.util package

Input/Output Feature with Strings

Booleans

Teacher: What are you looking at?
You already know.
Student tries to hide it.
Teacher: I want to ask you something.
Look at it.
Please turn it off...remember the course syllabus.
Before you turn it off, do you see two numbers in the Power off button?
Student: Numbers?
I do not see numbers.
It's an icon.
Teacher: Yes, they are numbers.
The numbers are: $0$ and $1$
$1$ is inside the $0$ in most devices.
Student: Interesting.
Teacher: $0$ represents OFF
$1$ represents ON
You see these two numbers in almost all electronic devices (tablets, smartphones, computers) including some electric switches.
In Logic, $0$ represents FALSE
$1$ represents TRUE
We use true and false Boolean values in Statements including conditional statements and iterative statements. We shall cover Statements in the next module.
The use of these two numbers: $0$ and $1$ in Mathematics and Computer Science to repesent FALSE and TRUE values is known as Boolean Algebra
It was developed by George Boole, an English mathematician/philospher/logician.
We can also use these Boolean numbers $0$ and $1$ to represent choices/options of NO and YES


A Boolean is a fundamental data type in Java that:

(1.) is declared with the keyword, bool

(2.) can represent only one of two states: true or false

(3.) gives an output of only one of two values: true or false

(4.) is used for comparison (in relational and comparison operators) to compare expressions.

(5.) is used in statements (conditional statements and iterative statements) to make decisions.

A Boolean Expression is an expression that returns a Boolean value.

Let us demonstrate some examples of the use of Booleans.

Booleans: Example 1




Booleans: Example 2

Date and Time

Date and time stamps are needed for: transactions, receipts, appointments, agreements, events, rules/laws, and tickets (by cops and troopers) among others.
Besides, we shall use the date and time functions in the midterm project.
Let us discuss date and time.

Teacher: The date and time is interesting in the sense that I would not classify it as a string or as an integer.
Student: What data type would you call it?
Teacher: It is a data type by itself.
However, you can treat it as a string and use certain string functions with it.
You can also treat it as an integer by adding or subtracting days and years.

There are several approaches to display date and time in Java.
Let us discuss two appraches.

First Approach: java.time package
To display date and time in Java, we need to import the java.time package.
The java.time package includes several classes to access date and time.
Some of the classes included in the java.time package are:
(1.) LocalDate: This displays the date in the format: yyyy-MM-dd (year, month, day format)

(2.) LocalTime: This displays the time in the format: HH-mm-ss-ns (hour, minute, second, nanosecond format)

(3.) LocalDateTime: This displays the date and time in the format: yyyy-MM-dd-HH-mm-ss-ns (year, month, day, hour, minute, second, nanosecond format)

These classes use the now() method to get the current date and time.

(4.) DateTimeFormatter: This uses the ofPattern() method to format the date and time objects and display them in several formats.
However, we have to create a String variable that formats the LocalDate or LocalTime or LocalDateTime object with the object of the DateTimeFormatter using the .format method.

Please review the screenshots and the comments.

Date and Formatted Date



Time and Formatted Time



Date and Time, and Formatted Date and Time





Let us review more approaches to handling date and time in Java
Date, Time, and Time Zone
We need to import the Date class of the java.util package


Format the Date, Time, and Time Zone
We need to import an additional class: the DateFormat class of the java.text package


As at today: 03/01/2021; Kent State University has 8 Ohio campuses, several other U.S campsuses, and four campuses outside the United States otherwise known as Kent State Worldwide.
Kent State Worldwide consists of Kent State in Florence, Italy; Geneva, Switzerland; New Delhi, India; and Beijing, China.
Mr. C wants to greet all his students in the United States and Worldwide.
He wants to great them in their local dates and times.
He would kindly ask you, his student (please check out one of the Questions in the Assess tab) to teach him the greeting in your language.
But his work right now is to display the date and time of each country: United States, Italy, Switzerland, India, and China.

Because we shall be working with foreign countries, we need:
(1.) Time zone of each country.
TimeZone represents a time zone offset, and includes daylight savings.
As at today: 03/04/2021; the time zone IDs that are available in Java are:

Note that these time zone IDs should be entered as strings.
If the country is not listed, then we will need to use the UTC (Universal Time Coordinated) and include any offset as applicable.
How?
Bing or Google "time zone for country" and look for the UTC time zone of that country.
If it is UTC+4, then use UTC+4 for that time zone. It should work in Java.
Alternatively, contact Oracle and ask them to include your country/city/county/province/region.

(2.) Current date and time (date and time now) of each country.

(3.) Locale of each country.
A Locale object represents a specific geographical, political, or cultural region.
Typically, it has three arguments though it can take one or two arguments.
We shall use the Locale object with two arguments as: Locale dateTimeCountry = new Locale("language", "countryCode");
This is the List of Countries, Languages, and Locale for Displaying Date and Time
(https://www.samdomforpeace.com/References/ASCII.html#specificCulture)

(4.) Necessary packages: As we write our code, the necessary classes of the Java packages will be added (imported) to the code.
If they are not, we will have to add them manually.

Please Explore
That is one of the ways to learn the Java programming language well.
The DateTimeFormatter class has several methods.
I encourage you to explore the methods so you see the several formats that you can use for the date and time.
Please explore the methods of the other classes that we used.
Type the class such as: DateTimeFormatter and then type the dot access member operator (the decimal point on your keyboard) and you will see the methods.
Have fun exploring 😊

Please review the screenshots and the comments.

Date and Time: Example 1: Current Date and Time in Different Countries








Student: What if we want to display the date and time in several states across the United States?
Our students come from all 50 states of the United States as well as the United States territories.
And you know there are different time zones in the United States.
How do we display the current date and time in those states in their respective time zones?
Teacher: Very good question.
Say we want to find the date and time in the State of Alabama.
The State of Alabama is in the Central time zone. The time is Central Standard Time (CST)
First, we get the ZoneId of the time zone.
ZoneId timeZone = ZoneId.of("US/Central");

Then, we get the current date and time based on that time zone.
ZonedDateTime stateAlabamaDateTime = ZonedDateTime.now(timeZone);

Then, we create an object of the Locale class and use the specific culture as the parameter.
Locale dateTimeAL = new Locale("en", "AL");

Then, you complete it accordingly...just as we did in the Example $1$

This is the List of the States and Territories of the United States for Displaying Date and Time
(https://www.samdomforpeace.com/References/ASCII.html#specificCultureUS)

Let's develop another date and time function application.
What are some of your memorable events? dates for those events?
Student: Birthday, Christmas...I'm always looking forward to it
Teacher: Let's write a program in that regard.
I shall use my birthday as an example.
Let us calculate how many days there are until my birthday.
We shall begin with a console application.
Then we shall develop a desktop application and explore more toolbox controls.
An interesting toolbox control to explore is the Timer.
Have you noticed those websites where you see a timer that displays a countdown of the times: days:hours:minutes:seconds to a particular event?
Student: Yes, I have.
Teacher: Cool. So, we shall explore that control and some other controls for the GUI.
As at today: 03/02/2021, my birthday is yet to occur. However, it is important to add a functionality to the program to display a message to the user if the user's birthday has already occurred prior to today.
Student: I guess we shall ask the user to enter the birthday?
Teacher: Yes. Let's use an Input/Output feature to make it interactive.
The program will ask the user to enter the birth year, birth month, and birth day.
If the birthday has already occurred, inform the user accordingly. Then, display a positive message informing the use that we look forward to his/her next "age" birthday.
If the birthday is yet to occur, display the number of days remaining until the birthday.
If the user's birthday is today, we shall greet the user with a HAPPY BIRTHDAY greeting.
This will require a conditional statement.
Student: You know Mr. C, we have been using Statements since Module 3 when we are supposed to cover it in Module 5.
Teacher: That is correct. It goes to show how important they are in programming.
It is okay to introduce you to them so you get familiar with using them.
We shall cover them in detail in Module 5. It is a broad topic.
Please review the screenshots and the comments.

Date and Time: Example 2: Birthday Application

GUI Programming:

Required Substantive Posts

You may use strings not written in English language. However, if you use any language other than English language, please make sure you translate it. Your colleagues and I need to understand any language you use.
Insensitive words or any word deemed inappropriate to any race, gender, religion, and national origin among others are unacceptable. Any violation will not yield any point.
If you are not sure of the words/string to use, please contact me first.

Remember DB 3 Requirement. There are enough methods for everyone. If all the methods are done, please attempt another question.

Please review the:
Java String methods by W3Schools
(www.w3schools.com/java/java_ref_string.asp) and/or
Java String methods by Beginners Book
(www.beginnersbook.com/2013/12/java-strings/) and/or
Java String methods by Oracle
(https://docs.oracle.com/javase/9/docs/api/java/lang/String.html)
(Scroll down till you see the tab: All Methods)

(1.) Review the methods and the examples.
Pick any five methods besides the ones I discussed.
Write the code examples for each method and implement each of them.
Run your codes.
Display the results.
Submit clear screenshots of your code examples of each of the five methods and the corresponding results.

Please review the:
Java StringBuffer class by Tutorialspoint
(www.tutorialspoint.com/java/lang/java_lang_stringbuffer.htm) and/or
Java StringBuffer class by Oracle
(https://docs.oracle.com/javase/7/docs/api/java/lang/StringBuffer.html)
(Scroll down till you see the tab: Method Summary)

(2.) Review the methods and the examples.
Pick any five methods besides the ones I discussed.
Write the code examples for each method and implement each of them.
Run your codes.
Display the results.
Submit clear screenshots of your code examples of each method and the corresponding results.

Please review the:
Java StringBuilder class by Tutorialspoint
(www.tutorialspoint.com/java/lang/java_lang_stringbuilder.htm) and/or
Java StringBuilder class by Oracle
(https://docs.oracle.com/javase/7/docs/api/java/lang/StringBuilder.html)
(Scroll down till you see the tab: Method Summary)

(3.) Review the methods and the examples.
Pick any five methods besides the ones I discussed.
Write the code examples for each method and implement each of them.
Run your codes.
Display the results.
Submit clear screenshots of your code examples of each method and the corresponding results.

Textbook Questions
(4.) Question 2 on Page 362

(5.) Question 4 on Page 362

(6.) Question 6 on Page 363

(7.) Please review the Date and Time example in this module.
Our students come from the entire 50 states of the United States and its territories.
However, the United States has different time zones.
Find out/browse/learn/discover the different time zones in the United States and its territories as seen in the The Official U.S. Time (https://time.gov/) according to the National Institute of Standards and Technology
Include those time zones in your comments.
Display the current date and time for each time zone.
Verify your answer with the times and time zones on that website.

Java Programming Exercises, Practice, Solution by W3Resource
Please review:
(A.) Java Strings: Exercises, Practice, Solution
(B.) Java Date and Time: Exercises, Practice, Solution
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(8.) Write the Question as a comment in your program. Include the Title and the Question Number.
Write clear comments for each line of code in the Solution.
Run the program.
Submit clear screenshots.

For those who do not mind messing around with several languages at the same time
Student: Excuse me, Mr. C
This course is only for Java
What do you mean?
Teacher: You are correct.
But, these subsequent questions are not for everyone.
That is the reason I am putting them at the end.
I have a question for you.
Have you ever seen any IT/Computer Science position that requires the knowledge of only one programming language?
Student: I have not checked, Sir.
Teacher: If you intend to be in the IT/Programming field for the long run, at least four (four or more) languages are required.
If you look for IT positions at Indeed.com or other career/job websites, you will realize what I mean.
Search for java programmer, you might be surprised that even for entry level positions for a Java Programmer; they require you to have a working knowledge of several other programming languages.
Mr. C is preparing you for that...if you intend to work in the programming field for a long time.
Besides, this is a critical thinking approach.
I am required to develop and promote critical thinking questions for my students.
A programmer is basically a problem-solver irrespective of the programming language used to solve the problem.
Yes, we are working with Java. However, if you find out that C# would be better in solving a particular problem in your workplace, then you need to use C# unless your employer says otherwise.
The knowledge of several languages is a good asset. It makes you highly valuable.
Further, anyone who attempts any of the subsequent questions will still have to write the program in Java and get the same result.
The questions and solutions are in another language.
But the student will have to write the program in Java and come up with the same solution. So, we are still on track.
It is critical thinking...multiple approaches to solving a question.
Be it as it may, these subsequent questions are not required.
It is okay even if you do not look at them. 😊

C# Programming Exercises, Practice, Solution by W3Resource
Please review:
(A.) C# Strings : Exercises, Practice, Solution
(B.) C# Date and Time: Exercises, Practice, Solution
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(9.) Write the Question as a comment in your program. Include the Title and the Question Number.
Write the program in Java
Run the program. Please make sure your program output is the same solution
Submit clear screenshots.

C++ Programming Exercises, Practice, Solution by W3Resource
Please review:
(A.) C++ Strings: Exercises, Practice, Solution
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(10.) Write the Question as a comment in your program. Include the Title and the Question Number.
Write the program in Java
Run the program. Please make sure your program output is the same solution
Submit clear screenshots.

Required Substantive Responses

(1.) Review the post (Discuss Questions) done by your colleagues.
Use a different string method to work on the same string used by your colleague.

(2.) Review the post (Discuss Questions and Assess Questions) done by your colleagues.
If your colleague developed a console application for a program, develop a desktop application for the same program.
If your colleague developed a desktop application for a program, develop a console application for the same program.

(3.) Other substantive responses.

Check Your Understanding

You may use strings not written in English language. However, if you use any language other than English language, please make sure you translate it. Your colleagues and I need to understand any language you use.
Insensitive words or any word deemed inappropriate to any race, gender, religion, and national origin among others are unacceptable. Any violation will not yield any point.
If you are not sure of the words/string to use, please contact me first.

(1.) We are yet to do Statements (in the next Module), but you can give this question a try.
A string palindrome is a word, phrase, clause or sequence of characters that is spelled and read the same way backward and forward.
In other words, when one reads it as is, reverses it and reads it again; the pronunciation is the same.
Examples include the:
Words: HANNAH, BOB, madam, level, civic, racecar, rotor
Phrase: never odd or even
Clause: nurses run
Sentence: Was it a car or a cat I saw?

Write a Java program that asks for user input.
Determine if the user input is a string.
If the user input is not a string, ask the user to enter only a string.
If the user input is a string, determine if it is a string palindrome.
Inform the user whether it a string palindrome or not.
Test at least one example of: Words, Phrase, Clause, and Sentence that was listed.
This implies testing at least four examples.
Submit clear screenshots of the code and the results.

(2.) Please review the Date and Time: Example 1: Current Date and Time in Different Countries
Extend my application by greeting your fellow colleagues in the langauge of their countries.
Due to the nature of the Hindi and Chinese alphabets, do not worry about India and China.
Write a Java application that:
(a.) Displays the date and time for the countries: United States, Italy, and Switzerland.
Because you are extending my application, you may use my code.
Find out/browse/learn/discover the greetings for Good Morning, Good Afternoon, and Good Evening for Italy and Switzerland in Italian and German respectively.
(b.) Displays the greetings to each user (your fellow colleague) according to the current time.
If the time is between 12:00:01 AM to 12:00:00 PM (inclusive), greet Good Morning in each langauge.
If the time is between 12:00:01 PM to 04:00:00 PM (inclusive), greet Good Afternoon in each lanaguage.
If the time is between 04:00:01 PM to 12:00:00 PM (inclusive), greet Good Evening in each language.
Explore the time formats of the DateTimeFormatter class or any other applicable Java class.
You may use 12-hour or 24-hour time formats.
These are the minimum requirements. You are welcome to add more functionalities.

(3.) Please review the Date and Time example in this module.
Our students come from the entire 50 states of the United States and its territories.
However, the United States has different time zones.
Find out/browse/learn/discover the different time zones in the United States and its territories as seen in the The Official U.S. Time (https://time.gov/) according to the National Institute of Standards and Technology
Include those time zones in your comments.
Display the current date and time for each time zone.
Greet each user (your fellow colleague) according to their time zones (their own current times).
If the time is between 12:00:01 AM to 12:00:00 PM (inclusive), greet Good Morning.
If the time is between 12:00:01 PM to 04:00:00 PM (inclusive), greet Good Afternoon.
If the time is between 04:00:01 PM to 12:00:00 PM (inclusive), greet Good Evening.
You may use 12-hour or 24-hour time formats.
These are the minimum requirements. You are welcome to add more functionalities.

(4.) Please review the Date and Time: Example 2: Birthday Application
Modify my application or write your new application.
(a.) Ask the user to also enter the time (hh:mm:ss) in hours, minutes, and seconds that he/she was born.
(b.) If the user has not had birthday this year, inform the user about the number of days, hours, minutes, and seconds until his/her birthday.
Do not stress about the calculations. Java has classes and methods that handle most of these calculations.
(c.) If the user already had birthday this year, or if today is the user's birthday; display appropriate positive messages to the user.
(d.) A user's birthday is 29th February. This implies that the user has to celebrate birthdays only on leap years (years that are divisble by 4). Accommodate that user in your application. Display message(s) accordingly.
(e.) Include checks for user-input errors and display messages accordingly.

(5.) Write a Java program that solves Question (8.) on the Applications of Numbers website.
(https://numbersandnotations.appspot.com/numbersApplications.html)
Use any actual date that is a Tuesday.
Ensure that the output of your program corresponds to the solution on the website.
Please display: the actual date, the actual day, the new date and the new day in your output.
In other words, I am looking for the input date, the input day that is a Tuesday, the output date, and the output day that is a Friday.
Please check to ensure your program gives the correct output (result).
You may develop a console application or a desktop application for this program.
Submit screenshots of the question, your program, and the output of your program.

(6.)

Vocabulary Words

statement, expression, block, expression statement, assignment statement, increment and decrement statements, method invocation statement, object creation statement, declaration statement, control flow statement, decision-making statements, conditional statements, decision, selection statements, looping statements, branching statements, branches, repetitive statements, iteration statements, loops, for loop, while loop, do-while loop, for-each loop, jump statements, break, continue, ternary operator

Objectives

Students will:

(1.) Discuss Statements in Java programming language.
(2.) Write decision-making statements.
(3.) Write looping statements.
(4.) Write branching statements.
(5.) Write programs that solve real-world problems using statements.
(6.) Complete the Midterm Project on Piecewise Functions.

Recommended Readings

(1.) Textbook Chapter

(2.) Expressions, Statements, and Blocks
(https://docs.oracle.com/javase/tutorial/java/nutsandbolts/expressions.html)
Begin from Expressions, Statements, and Blocks to Questions and Exercises

(3.) Java If...Else
(www.w3schools.com/java/java_conditions.asp)
Begin from Java If...Else to Java Break/Continue

Videos:
Please click the RESOURCES tab of this website
Click the LinkedIn Learning (Kent State University) link
Follow the directions to access the website.
(4.) Type Java Statements in the search bar and view the results.

Videos and Textbooks:
Please click the RESOURCES tab of this website
Click the O'Reilly Online Learning link
Follow the directions to access the website.
(5.) Type Java Statements in the search bar and view the results.

Required Readings

Expression
An expression is a construct made up of variables, operators, and method invocations, which are constructed according to the syntax of the language, that evaluates to a single value.
// Expression
// We covered this statement in Module 3
double result = 7 * (5 - 2); // 21

Statement
A statement is an individual instruction of a program.
It ends with a semicolon.
It forms a complete unit of execution.
It is equivalent to a sentence in a language.

There are three kinds of statements in Java.
They are:
(1.) Expression Statements
These are statements that are made from expressions.
They include:
(I.) Assignment statement
// Assignment statement
// We covered this statement in Module 3
int num1 = 7;

(II.) Increment and Decrement statements
// We covered this statement in Module 3
// Increment statement
num1++;
// Decrement statement
num1--;

(III.) Method invocation statement
// Method invocation statement
// We have been using this statement since Module 1
System.out.println("THANK GOD");

(IV.) Object creation statement
// Object creation statement
// We used this statement in Modules 3 and 4
import java.util.Scanner; // Import the Scanner class of the java.util package
// Create the object: userInput of the Scanner class
Scanner userInput = new Scanner(System.in);


(2.) Declaration Statements
A declaration statement declares a variable.
// Declaration statement
// We covered this statement in Module 3
int num1 = 7;


(3.) Control Flow Statements
Generally, statements in Java are executed from top to bottom, in the order that they appear.
However, control flow statements control the order in which statements are executed.
In other words, they break up the flow of the execution of statements by using decision making, looping, and branching; thereby allowing a program to execute particular blocks of code conditionally.
They include:
(I.) Decison-making Statements
The decision-making statements are the: if statement, if-else statement, if-then statement, if-then-else statement, Multiple ifs statement, and the switch statement
These statements are also referred to as Conditional statements or Decisions or Selection statements

(II.) Looping Statements
The looping statements are the: for loop, while loop, the do-while loop, and the for-each loop
These statements are also referred to as Repetitive statements or Iteration statements or Loops

(III.) Branching Statements
The branching statements are the: break statement, continue statement, and the return statement
These statements are also referred to as Jump statements or Branches

Block
A block is a group of zero or more statements between balanced braces that can be used where a single statement is allowed.
In Example 3 (If-else statement) as seen in the screenshot below; the if statement is the first block of code and the else statement is the second block of code.

Decision-making Statements

Decision-making statements are statements that execute an action based on some condition(s).
They are also known as Conditional Statements or Decisions
These statements are the:
(1.) If statement
This statement is used when there is only one condition.
If some condition is met, execute a given task.
The If statement is written as:

                            if (condition) 
                            { 
                                statement;
                            }
                    

Java ignores whitespaces so you can also write it this way:

if (condition) { statement; }

(2.) If-else statement
This statement is used when there are only two conditions.
If first condition is met, execute a given task.
else execute another task.
The else refers to the other condition.
Please note that we do not specify the condition for the else statement because we already know it is the other (remaining) condition.
The If-else statement is written as:

                        if (condition) 
                        {
                            statement;
                        } 
                        else 
                        {
                            statement;
                        } 
                        

Java ignores whitespaces so you can also write it this way:

if (condition) { statement; } else { statement; }

We can also write simple If-else statement using the Ternary operator
It can be used for simple if-else statements.
The syntax is:

                        variable = if (condition) ? statement if true : statement if false;
                    

(3.) If-else if-else statement
This statement is used when there are more than two conditions in which the first condition is used for the If statement, other conditions are used for the else if statements, and the last condition is used for the else statement.
Please note that the last condition for the else statement is not specifid in the code because it is the remaining condition.
It is generally known as the remaining condition after all other conditions are specified.
Assume we have only four conditions for a particular program:
The If-else if-else statement is written as:

                        if (condition 1) {
                            statement;
                        } else if (condition 2){
                            statement;
                        } else if (condition 3) {
                            statement;
                        } else {
                            statement;
                        } 
                    

Whitespaces are ignored in Java. Therefore you can also write it this way:

                        if (condition 1) { statement; } 
                        else if (condition 2) { statement; } 
                        else if (condition 3) { statement; } 
                        else {statement; }
                    

Keep in mind that we do not specify condition 4 in the code for the else statement because we already know that the else statement would only be executed if all the other prior conditions are not met.

(4.) Multiple Ifs statement
This statement is used when there are more than two conditions in which each condition is uniquely different.
You can also use this statement if you are not comfortable using the If-else if - else statement.
Both statements accomplish the same task.
Assume we have only four conditions for a particular program:
The Multiple Ifs statement is written as:

                        if (condition 1) 
                        {
                            statement;
                        }
                        if (condition 2){
                            statement;
                        }
                        if (condition 3) {
                            statement;
                        }
                        if (condition 4) {
                            statement;
                        } 
                    

Whitespaces are ignored in Java. Therefore you can also write it this way:

                        if (condition 1) { statement; } 
                        if (condition 2) { statement; } 
                        if (condition 3) { statement; } 
                        if (condition 4) { statement; }
                    

Review the Definitions of Numbers
(www.numbersandnotations.appspot.com/#definitions)
Conditional Statements: Example 1 (If statement)



Student: What if the user enters 5?
Teacher: Very good question.
What do you think?
Student: I'm not sure.
But, I'm guessing it will not run.
Teacher: The program will still run.
However, there will be no output.
Do you know the reason?
Student: Because there was no condition in the If statement to check for that?
Teacher: That is correct.
We did not specify what should happen if number is 0 or if number is greater than 0.
We need to specify all conditions.
Let's check it out

Conditional Statements: Example 2 (If statement is NOT enough for this example)



Teacher: As we can see, it did not display any output.
How do we take care of this?
Student: Include the condition in the conditional statement
Teacher: I know. 😊
How do we include it?
Let us see what we can do.

Conditional Statements: Example 3 (If-else statement)





Student: But, Mr. C; what if I do not want to use the If-else statement?
What if I decide to use Multiple Ifs statements for that same example?
Will it not work?
Teacher: It will work.
You can use Multiple Ifs statements if you know you will cover all the conditions.
It will give the same output as the If-else statement.
Let us try it.

Conditional Statements: Example 4 (Multiple Ifs statements)





Teacher: Let us rewrite Example 3 using the Ternary operator
The Ternary operator is the short hand approach of writing an if-else statement.

Conditional Statements: Example 5 (If-else statement using the Ternary operator)





Let us look at more examples.
Recall: In English Language, Finite Mathematics, Discrete Mathematics; some of the ways to join simple statements to make a compound statement are:
(I.) Use of the conjunction, and which is denoted by && in Java
(II.) Use of the disjunction, or which is denoted by || in Java

Let us review an example where we shall use the conjunction, and

Conditional Statements: Example 6 (If-else statement and the use of the conjunction, and (&&))





Student: What if we have a set of numbers and we want to see if those numbers are positive odd numbers?
Teacher: Great question.
That brings us to an array or list of numbers.
The use of arrays and loops is a more efficient approach of solving those kinds of questions.
We shall cover arrays in another module.
However, we can still do something here.
We shall use two variables to capture two user-input values.
Let us try it with two numbers.

Conditional Statements: Example 7 (Multiple If-else statements, use of "and" (&&))




Student: What if the user enters a decimal?
Teacher: Good question.
What do you think?
Student: Mr. C...
The teacher that answers questions with questions
Teacher: It is a teaching technique. 😊 I do that sometimes but not all the time
So, what do you think?
Student: I feel it will not work
Teacher: That is correct.
The program will not run
It will not execute, not to mention give an output.
Instead, the IDE compiler will throw an exception because we defined the user input as an integer data type rather than as a double data type.
It is one of the mechanisms of Exception Handling.
Student: What is Exception Handling?
Teacher: It is the response to exceptions during run time (when a computer program runs).
Student: What are exceptions?
Teacher: In simple terms, exceptions are errors such as user-input errors, file system errors, and division by zero among others.
We've been handling user-input errors...remember the BMI application we did in Module 3?
We did not call it an exception because we are yet to cover the topic of Exception Handling.
We shall cover some of it in this Module and the rest of it in the Advanced Java course.
Let us discuss a real-world application of selection statements that will lead us to your Midterm project.

Piecewise Functions

A good application of C# Selection Statements is seen in Piecewise functions.
Please review the Story on Piecewise Functions
(www.piecewise-functions.appspot.com/#story)
We are going to write several C# programs that will solve the Piecewise function problem in that story.

Piecewise Function: Selection Statements using Multiple Ifs statements
Conditional Statements: Example 8 (Multiple conditions: Multiple ifs)






Let us address user-input errors for the number of burritos that may be out of range in the Piecewise Function.
It is important to address user-input errors in any program you write.
In this case (for the Story on Piecewise Functions): the program will not display any output if the user enters a negative number, a zero, or any positive number greater than the upper bound of the last piece.
The user may then be confused if he/she does not see any output.
We want to avoid that.
In the case of user-input error, we want the program to display a message that the user entered something out of range, and then exit without interrupting the system.
Hence, we wrote the message for the user and included the System.Exit(0); method to exit the program.

What if the user enters $2500$?


What if the user enters $-3$?


Student: Can we write the same Piecewise function using the If-else if-else statements?
Teacher: Nice question.
What do you think?
Student: I think we can.
Teacher: Yes but we need to include the last else statement
Student: Must we include it?
Teacher: Highly recommended...yes
However, the program will work even if we do not include it.
But my recommendation is that whenever you use if-else statement, make sure you include the last else statement
In this case (using the if-else if-else statement), the last elsestatement will have a statement but not a condition.
It is executed when all prior conditions are not met.
So, let us write a statement that will display the message to the user if the user enters any value that is out of range. using the If-else if-else statements

Piecewise Function: Conditional Statements using If-else if-else statements
Conditional Statements: Example 9 (Multiple conditions: If-else if-else statements)






What if the user enters $0$?


What if the user enters $3000$?


What if the user enters $-12$?


Teacher: Did you notice the importance of that final else statement?
We did not need to specify the range of numbers that are out of bounds as we did for the Multiple Ifs statements.

(5.) Switch statement
Another selection statement is the switch statement.
It works with the: byte, short, char, and int primitive data types and the String class.
It also works with the enumerated types (discussed in Enum Types), and a few special classes that wrap certain primitive types: Character, Byte, Short, and Integer.
The body of a switch statement is known as a switch block.
A statement in the switch block can be labeled with one or more case or default labels.
It evaluates its expression, then executes all statements that follow the matching case label.
A swich statement is terminated by a break statement.
If the break statement is not used, then all the statements after the matching case label are executed in sequence, regardless of the expression of subsequent case labels.
So, each break statement is required after each case label besides the final case label or the default label.
The default section handles all values that are not explicitly handled by one of the case sections.
The final break is not required for the final case label or the default label because the flow falls out of the switch statement.
The use of the break statement is also recommended to easily modify the code and make it less error prone.

Which selection statement should you use? If-else or Switch statement?
The option to use if-then-else statements or a switch statement depends on the readability and the expression that the statement is testing.
An if-then-else statement can test expressions based on ranges of values or conditions, while a switch statement tests expressions based only on a single integer, enumerated value, or String object.

The general syntax of the switch statement for the Integer data types (Byte, Short, and Integer data types) is:

                            // This variable should be declared with any of the Integer data types
                            variable 
                            switch (variable){
                            case 1: 
                            	statement;
                            	break;
                            case 2:
                            	statement;
                            	break;
                            case 3:
                            	statement;
                            	break;
                            default:
                            	statement;
                            }
                        

Case 1
The switch block compares the value of the variable with 1
If the value of the variable is 1, then it executes the statement in case 1 and breaks, thus ending the program.
If the value of the variable is not 1, it moves on to case 2 and compares the value of the variable with 2
If the value of the variable is 2, it executes the statement in case 2, breaks, and ends the program.
Otherwise, it moves to case 3.
It compares the value of the variable with 3
If that value is 3, it executes the statement in case 3 and breaks. The program ends.
If that value is not 3, it executes the statement in the default
As noted, the break statement ends the program when the value of the variable is equal to the case number, otherwise the switch statement moves on to the next case and continues the comparison.

Teacher: Have you noticed these Call Center greetings?
For English, press 1; Para Español, marque dos.
Student: Yes I have.
You mean to say: For Spanish, press 2.
Teacher: Yes.
Let us write a simple application for that greeting using a simple Select-Case statement.
We can add more simple features..."spice it up".

Switch Statements: Example 1: Call Center Greetings







Let us review more examples of the switch statement

Let us write a Switch statement that involves the use of the String data type variable.
Rather than asking for user-input, we can also initialize the variable.
Remember, we can use any of the variables we listed previously.





But, I really prefer the user-input feature. It makes for an interactive application.
Let us modify the application to accept user input.
In that case, we do not initialize the String variable.









Please answer these questions.
Review the last two slides of the output.

Question 1
(1.) Explain why the slide with the user-input of $52$ displayed that output.

Show/Hide Answer

Question 2
(2.) The user entered "africa" and expected to see the statement associated with that continent.
However, the user saw another output.
Explain.

Show/Hide Answer

Recall the Piecewise Function program we wrote earlier.
We used Conditional statements to write it.
Let us develop the same program using the Switch statement.
We shall use the Switch statement and the Ternary operator to write the program.

Piecewise Function Application using the Switch Statement and the Ternary Operator

Nested Conditional Statements

Nested If-Else Statements
We can write more challenging programs using Nested Selection Statements
We can use Nested If-Else statements

One of the syntax for Nested If-Else statement is:

                           dataType variable;
                            if condition 1{
                                If condition 2{ 
                                    statement;
                                }
                                else{ 
                                    statement;
                                }
                            } 
                                 
                            else if condition 3{ 
                                if condition 4{
                                    statement;
                                } 
                                else{ 
                                    statement;
                                }
                            } 
                            
                            else{ 
                                statement; 
                            } 
                        

Notice the order in which each nested conditional statement is closed.

Would you like to challenge yourself with nested conditional statements?
(Just for the fun. Not for a grade)
Develop Java programs that uses nested conditional statements to solve these applications.

(1.) Who qualifies for the $\$1,400$ payment under the American Rescue Plan also known as President Biden's stimulus bill?
Third Round of Stimulus Checks: American Rescue Plan
(https://money.yahoo.com/heres-who-gets-a-1400-payment-under-the-new-stimulus-deal-194708150.html)

(I.) Who likes to read?
(II.) Who likes bite-sized information? Who likes flowcharts/diagrams to represent information?
(III.) Who prefers to just use an application (app) and enter a few details to see if he/she qualifies?

Who would develop this application: (console, desktop, web, and mobile apps) by using (I.), (II.), and (III.)...the Programmer.
Develop a desktop application that addresses all those conditions, and informs any user if he/she qualifies to get the stimulus payment.
Notice how important you are 😊

(2.) Advising is not an easy work in tertiary institutions.
Placing students to take the correct courses for their majors is an important task.
You have to check the student's High School GPA, ACT/SAT test scores, tranfer credits/courses and grades if any, graduation date and previous courses, grades made in those courses, and the dates those courses were taken, prior experience in field as applicable, and degree in a related field as applicable among others.
Without an efficient/effective program to check all these conditions, it is possible for students to take courses that are irrelevant to their major/program.
Imagine if those students paid for those courses. That is similar to spending money on what you don't need.
The work of a programmer is to solve problems.
Do some research and study at least one advising task for a major at an institution.
Note all the conditions required for advising students enrolled in that major/department.
Develop a desktop application for advising students in that major.
Notice how important you are 😊

Looping Statements

Looping statements are:
(1.) For Loop
(2.) While Loop
(3.) Do-While Loop
(4.) For-Each Loop

(1.) The general syntax of a for loop is:

                            for (initializer; condition; iterator)
                            {
                        	    statement;
                            }
                        

This is also written as:

                            for (index = beginValue; condition; index compound_assignment someValue)
                            {
                        	    statement;
                            }
                        

(2.) The general syntax of a while loop is:

                            initializer;
                            while (condition)
                            {
                        	    statement;
                        	    iterator;
                            }
                        

This is also written as:

                            index = beginValue;
                            while (condition)
                            {
                        	    statement;
                        	    index compound_assignment someValue;
                            }
                        

(3.) The general syntax of a do-while loop is:

                            initializer;
                            do 
                            {
                        	    statement;
                        	    iterator;
                            }   
                            while (condition);
                        

This is also written as:

                            index = beginValue;
                            do 
                            {
                        	    statement;
                        	    index compound_assignment someValue;
                            } while (condition);
                        

(4.) The foreach statement executes a statement or a block of statements for each element in a collection (array)
The general syntax of a foreach loop is:

                            for(dataType variable : array)
                            {
                                statement;
                            }
                        

We shall implement the foreach statement in Module 7 (Arrays).

Example 1: Print the first ten positive integers using the three types of loops




Which of these types of loops do you prefer?

Let us do more examples.
For subsequent examples, we shall use the for loop and the while loop

Example 2: Print the even numbers between 1 and 20 (1 and 20 inclusive) using for loop and while loop




As you can see, we had to include conditional statement, if statement in the loop
Based on the defintion of an even number on the Numbers and Notations website (www.numbersandnotations.appspot.com/#definitions)
An even number is an integer divisible by 2 without a remainder.
It is important to include that condition in the loop
As the program loops through each number beginning with 1 and ending at 20; if each number is divisible by 2 without a remainder; the program will output it.

Example 3: Print the perfect squares between 1 and 100 (1 and 100 are inclusive) using for loop and while loop




We can also use decrement operators
We must not always increment.
For example: let us list all the multiples of 3 in descending order.

Example 4: Print the multiples of 3 between 1 and 36 in descending order (1 and 36 are inclusive) using for loop and while loop




Let us make this look nice.
In Nigeria, we had to recite Multiplication Tables (from 2 * 12 to 12 * 12) in the kindergarten/elementray school
These Multiplication Tables are written on the back of most exercise books.
Let us write the Multiplication Table for 7 (7 * 1 to 7 * 12)

Example 5: Print the Multiplication Table for 7 (7 * 1 to 7 * 12) using for loop and while loop

Branching Statements

Branching statements are statements that control the flow of a program by branching or performing jumps to specific locations.
They include:
(1.) The Break statement
(2.) The Continue statement

Branching statements are not standalone statements.
They are usually embedded in/used with conditional statements and looping statements.

Break Statement
The break statement breaks/stops a loop even when the loop is still running.
In other words, even if the conditions for a loop has not been satisfied, introducing the break statement at any point in the loop stops the loop and ends the program.
A good advantage of the break statement is that it can be used to end an infinite loop.

Continue Statement
The continue statement causes the program to skip a portion of the loop, and continue the loop.
In other words, using the continue statement does not run the entire loop. It skips some part of the loop and then allows the loop to continue.

Let us demonstrate these branching statements.
Please review all the screenshots and all the comments.

Branching Statements: Break Statement, Continue Statement





Let us redo one of the examples we did using Looping statements.
Let us redo the Example (2.) in Looping statements, with Looping and Branching statements.

Redo Example 2 in Iteration Statement using Iteration statement and Jump statement

Application of Statements : An Example : Solve a Mathematics Question

Let us solve Question (34.) on Arithmetic Sequences (www.samuelchukwuemeka.com/Sequences/arithmeticSequences.html) using selection statements, iteration statements, and jump statements.
We shall use iteration statements: for loop, while loop, and do-while loop to solve the question.
Then, we shall use iteration statements, jump statements and selection statements to solve the question.

Application of Statements: Calculate the sum of the $n$ terms of an arithmetic sequence.
Iteration Statements, Selection Statements and Jump Statements





Student: Mr. C, I understand the initialization of the number of terms...as given by the syntax for the loops.
But, why did we initialize the sum to 0?
Teacher: We initialized the sum to 0 because we have to increment each number and add.
$1 + 2 + 3 + 4 + ...$ is the same as saying $0 + 1 + 2 + 3 + 4 + ...$
Student: Why did we initialize?
Why can't we just declare the variable and keep adding the numbers?
Teacher: We have to use "something" to hold the sum.
Because we need to keep adding to "something", we need to initialize "that thing".
"That thing" is the "sum"
Student: The solution on your website used a formula to solve that question.
If we were using formula to solve it, do we need to initialize the sum?
Teacher: Good question.
We do not.
However, some compilers are picky and would insist that you do.
It is a good practice to initialize variables.
Student: Do we always have to intialize to $0$?
Teacher: We do not.
If we were going to multiply (rather than add) numbers...say we declare product as the variable rather than sum, then we have to initialize that variable to $1$ because we shall be multiplying numbers to it rather than adding numbers to it.
The number you use to initialize a variable is to just hold a value to that variable...more like a placeholder.
It does not determine or influence the final result of that variable.

Midterm Project

The midterm project is designed to assess your knowledge of Statements in solving real-world problems.
It is a Piecewise Function application.
Any other application will not considered.

Please:
(1.) Visit my website on: Piecewise Functions

(2.) Read the Story to understand the idea of Piecewise functions.

(3.) Read the Overview of Piecewise Functions for more understanding of Piecewise functions.

(4.) Study the Applications of Piecewise Functions

(5.) Review the Project Examples. Ensure you follow all the instructions and directions.

(6.) Review the Midterm Project rubric for your course.

(7.) Complete the Midterm Project for your course.

(8.) Ask questions. I can help.
If you have any issue at any time and you have reviewed the resources I provided and you cannot fix the issue, please attend the Office Hours/Live Sessions so I can help you.

(9.) Include all these: (documentation of all your Math work and the .exe file) in OneDrive, create a shareable link, and post the link in the Midterm Project Drafts forum of the course on Blackboard or send to me via email.
You may also upload them directly if you prefer.
I shall review and provide feedback.

(10.) Make sure your executable file runs by itself outside the project folder
If it does run, include these three items: single executable file (that runs by itself outside the folder), the Math documentation (Word document that has the Math part), and the entire project folder, into a folder, zip the folder (.zip extension only) and submit it in the appropriate area of the Blackboard course.
If it does not run, please fix it.
If you cannot fix it, please attend the Office Hours/Live Sessions so I can help you.

NOTE: Any actual project submitted to me via email will not be graded.

If you wish to save some time for research:
Please review the Piecewise Function projects done by my previous students.
The direct link of the verifiable websites are included.
(I.) VB Projects
(II.) C# Projects
(III.) C++ Projects
(IV.) Java Projects

You may not do any same application done by any of my previous students for Java
You may do any Piecewise Function application not done by any of my previous students for Java.
If you are not sure what project you may or may not do, please contact me via the school email.

Vocabulary Words

method, function, main method, system pre-defined method, user-defined method, common language runtime (CLR), method signature, method name, method parameter, parameter list, method access, access level, public, private, abstract, sealed, return value, return type, void, method invocation, instance method, static method, argument, argument list, pass parameters by value, parameter arrays, modifier, local variables, return keyword, value parameters,

Objectives

Students will:

(1.) Discuss methods.
(2.) Pass parameters to methods.
(3.) Overload methods.
(4.) Write programs that solves real-world problems using methods.

Recommended Readings

(1.) Textbook Chapter

(2.) Java Methods
(www.w3schools.com/java/java_methods.asp)
Begin from Java Methods to Java Recursion

Videos:
Please click the RESOURCES tab of this website
Click the LinkedIn Learning (Kent State University) link
Follow the directions to access the website.
(3.) Type Java Methods or Java Functions in the search bar and view the results.

Videos and Textbooks:
Please click the RESOURCES tab of this website
Click the O'Reilly Online Learning link
Follow the directions to access the website.
(4.) Type Java Methods or Java Functions in the search bar and view the results.

Recommended Readings

(1.) Textbook Chapter

(2.) Java Methods
(www.w3schools.com/java/java_methods.asp)
Begin from Java Methods to Java Recursion

Videos:
Please click the RESOURCES tab of this website
Click the LinkedIn Learning (Kent State University) link
Follow the directions to access the website.
(3.) Type Java Methods or Java Functions in the search bar and view the results.

Videos and Textbooks:
Please click the RESOURCES tab of this website
Click the O'Reilly Online Learning link
Follow the directions to access the website.
(4.) Type Java Methods or Java Functions in the search bar and view the results.

Required Readings

Methods

Teacher: Guess what?
Student: We have been using a method since we wrote our first Java program.
What is that method called?
Student: You mean the main method?
The static void main(String[] args)
Teacher: That is correct.
As we mentioned in the first module, every Java program is written in the main method.
The static void main(string[] args) method is the system pre-defined main method
The methods we shall discuss in this module are user-defined methods
The main method is the entry point for every Java application, and it is called by the common language runtime (CLR) when the program is started.
It is the only method that is called automatically regardless of the order in which it is written.
In other words, it does not matter if we write the main method before or after the user-defined method
The main method is called first by the Java program.
This implies that any other user-defined method should be called in the main method directly or indirectly. Note that we cannot use the reserved word, main as the name of any method we define (user-defined method).


A method is a block of code that contains a series of statements.
It is also known as a function.
It allows for the reusability of those statements/codes, and perform some action when called.
Reusability of codes: define one time, use many times.
Anytime the method is called, the statements in that method are executed.

Method Signature is the set of attributes used to declare a method.
They consist of the:
(1.) Access level: such as public or private.
By default, the access level is private.
The access level is optional.

(2.) Modifier: such as abstract or sealed.
The modifier is optional.

(3.) Return value or void
Every method must have either a return value or a void.
If the method has void, then it has no return value.

(4.) Method name: the name of the method.
It is important to use an appropriate identifier.
Method names (identifiers) in Java begin with an uppercase letter (preferably Pascal casing)
This is required.

(5.) Method parameters: Method parameters are enclosed in parentheses.
If the method has no parameter, then the parenthesis is empty.
This implies that a parenthesis is required.
If the method has parameters, the parameters are separated by commas.

We shall discuss some of the method signatures in this module.
We shall discuss the rest in the Advanced Java course.

Usually, a method takes in parameters.
Parameters are normally variables, and we declare them as we declare variables.
They are local variables to the method that takes them.
Student: To be honest, I have no idea what you just said.
What are parameters? arguments?
Teacher: Let us review this example.

Assume we have this program with a user-defined method:

                        // Method
                    
                        package methods;

                        public class Program
                        {
                            // Declare the method: SumNumbers 
                            // Parameters are: num1 and num2
                            public static int SumNumbers(int num1, int num2)
                            {
                                return num1 + num2;
                            }
                        
                            public static void main(String[] args)
                            {
                                // Call the method
                                // Arguments are 5 and 7
                                SumNumbers(5, 7);
                        
                                // Print what you called
                                System.out.println(SumNumbers(5, 7));
                            }
                        }
                        

In user-defined method:
In the public static int SumNumbers(int num1, int num2)
SumNumbers is the name of the user-defined method
int SumNumbers means that we want the method to return an integer
When we declared the method: SumNumbers; we passed in two parameters to it.
The parameters are: num1 and num2
Then we wrote a return statement that specifies what the method should return (the sum of the two parameter integers which also, is an integer)

Student: Question...Mr. C
Does it mean that we should know what the method should return before we declare it?
Teacher: That is right
Student: Can a method return more than one result?
Teacher: You are asking very good questions.
Yes, it can.
We can use the void type and include those results in a System.out.print() pre-defined method
Student: What if we do not want it to return anything?
Teacher: We can also use the void type as well.
We shall these cases in this module.

public is the access level of the method.
We shall discuss access levels later.
static means that it is a static method.
A static method is a method that belongs to a class but not an instance of the class.
A static method can only use and call other static methods.
The main method is a static method.
This implies that any user-defined method that we intend to call in the main method should also be a static method.
There are still more details regarding static methods. However, we shall discuss those details in Object-oriented programming in the Advanced Java course.

Student: What is an instance of the class?
Teacher: An instance of a class is called an object.
Student: What is an object?
Teacher: An object is an instance of a class.
Student: What is a class?
Teacher: Take my Advanced Java course. We shall discuss Object-oriented programming in details.
For now, let us just focus on Functional programming...programming based on functions (methods)
In the Advanced Java course, we shall discuss Object-oriented programming...programming based on classes and objects.
Actually, remember the Scanner class we use to accept user input?
It is a class. We had to create an instance of it, userInput and use it to accept the user input.
That instance of it is an object.
We can create as many instances as we want (many objects).

In the main method:
static void main(String[] args)
We know that it is the main method because of the keyword, main
It is a static method because of the keyword, static
It returns the void type because of the keyword void
This means that it does not have any single return data type: Integer, Double, String, etc.
However, it can return a statement that contains any or all of those return types in a String interpolation.
The arguments are: 5 and 7
Then, we can print the value of the method we called on those arguments using the System.out.println(); statement.
We can also assign an Integer data type variable to that method and just print the variable.
This is what I mean: int result = SumNumbers(5, 7);
System.out.println(result);
The code will give the same output.
So:
when we declare a method, we use parameters.
when we call that method, we use arguments.
A Parameter represents the value that the method expects you to provide when you call it.
The declaration of the method defines its parameters.
A method can be defined with no parameter, one parameter, or several parameters.
A Parameter List is the part of the method definition that specifies the parameters.

An Argument represents the value you provide to a method parameter when you call that method.
The calling code provides the arguments when it calls the method.
The arguments must be compatible with their respective parameter types.
An Argument List is the part of the method call that specifies the arguments.

To create a method that does not return a value (though it can also return multiple values in a System.print() method), we use the void keyword
To create a method that returns a value of a specific data type, we declare that method with that data type.

Student: Which one should we use? void or the specific data type?
Teacher: It depends.
To return multiple values in a System.print() method, the void keyword is needed.
To return a single value, you can use any of them: void or the data type.
Let us review some code examples.
Then, you can decide which one you would like to use for any program.

Definitions:
A local variable is a variable declared within a method.
A member variable is a variable declared inside a class or structure, but not within any method internal to that class or structure.
We shall focus only on local variables in this module.

Declaration syntax: The syntax for declaring a Void type method is:
accessLevel static void MethodName(parameterList)
{
     statements;
     Console.WriteLine($"something");
}

Declaration syntax: The syntax for declaring a Data type method is:
accessLevel static dataType MethodName(parameterList)
{
     statements;
     return something;
}

Void type Method Example

Celsius Temperature to Fahrenheit Temperature Conversion
Given: The Human Body Temperature in Celsius Temperature ($37^\circ$)
To Calculate: The Fahrenheit Temperature

Formulas:
$ fahrenheitTemp = \dfrac{9 * celsiusTemp}{5} + 32 \\[5ex] $

Data type Method Example

Fahrenheit Temperature to Celsius Temperature Conversion
Given: The Human Body Temperature in Fahrenheit Temperature ($98.6^\circ$)
To Calculate: The Celsius Temperature

$ celsiusTemp = \dfrac{5 * (fahrenheitTemp - 32)}{9} \\[5ex] $


Teacher: Did you notice the difference?
Student: Yes...I think so
I prefer the Void type method
We can easily use the variable names rather than writing the value. I mean ...
I would prefer to use the variable: fahrenheitTemp rather than 98.6
Teacher: I prefer the void method too
It helps if we want to return multiple values along with a message in a System.print() method
Let us write a code example that uses an Input/Output feature.
We shall also demonstrate the use of local variables.

Void Type Methods Example: Input/Output Feature

Formulas:
$ fahrenheitTemp = \dfrac{9 * celsiusTemp}{5} + 32 \\[5ex] celsiusTemp = \dfrac{5 * (fahrenheitTemp - 32)}{9} \\[5ex] $

Data Type Method Example: Input/Output Feature

Discriminant of a Quadratic Trinomial (no worries, we do not discriminate in Mathematics 😊)
Calculate the Discriminant of a Quadratic Trinomial in General Form

Why Are We Learning Methods?

(1.) Program Requirement
Every line of executable code in any Java application must be inside some method.

(2.) Reusability: write one time, use several times
Methods are useful for performing repeated or shared tasks such as frequently used calculations, text and control manipulations, and database operations.
We can just define a method one time, and then reuse the statements inside the method as many times as we want whenever we call that method.

(3.) Easier Code Readability and Faster Debugging
Imagine a "big" program (program with long lines of codes).
Methods allow such programs to be broken into discrete logical units.
This helps for easier code readability and faster debugging.

(4.) Avoiding Code Duplication
After developing a method in one program, it can be reused in another program with little or no modifcation.

Passing Parameters: By Value or By Reference

Generally, there are two ways of passing parameters: By Value and By Reference.
However, in Java; parameters are passed only by value.
In the previous examples we did, we passed the parameters by value.
In passing a parameter by value:
(1.) Protection: Exposure of calling variables to change
The advantage of passing a parameter by value is that it protects a variable from being changed by the method.

(2.) If the calling code element underlying the argument is a nonmodifiable element, declare the corresponding parameter by value.
No code can change the value of a nonmodifiable element.

If you would like to know how to pass parameters by reference, please review the notes in my VB.NET and C# courses.

Method Overloading

GUI Programming:

Some Substantive Posts

For all applicable questions, please:
(A.) Use the Void type and/or the Data type as your method
(B.) Use appropriate method names in line with Java naming conventions.
(C.) Include an appropriate message with your result.
(D.) Use an Input/Output feature if you wish.

(1.) Using Data Type Method Example: Input/Output Feature, include a condition that asks the user if the quadratic trinomial is in general form.
If the user says No, ask the user to arrange the quadratic trinomial in general form before proceeding. Then, quit the program.
If the user says Yes, proceed to run the program.
Test both conditions.

Arithmetic: Questions (2.) through (5.)
Please review the Definitions of Numbers on Numbers website: Numbers and Notations
(https://numbersandnotations.appspot.com/#definitions)
Please make sure you indicate the type of number in your comments.

(2.) Write a method that prints any of those types of numbers between one and thirty ($1$ and $30$ are included)

(3.) Write a method that prints the first thirty numbers of any of those types of numbers.
Focus on the first positive thirty numbers of those kind of numbers.

(4.) Write a method that asks the user to input two values (those values could be positive, zero or negative)
The method should print all the numbers for any of those types of numbers between those two values.
Those two values should be included if they are part of those type of numbers.

(5.) Write a method that asks the user to put in a value (that value could be positive, zero, or negative)
The method should print thirty values of those types of numbers up to and including the user-input value.

Geometry: Questions (6.) and (7.)
Please review the Mensuration Formulas on Mensuration website: Mensuration
(https://www.samuelchukwuemeka.com/Mensuration/mensuration.html)
Please make sure you indicate the type of figure/shape in your comments.

(6.) Write a method that asks the user to input the required parameters for any two-dimensional figure.
The method should return the area and perimeter of that figure.

(7.) Write a method that asks the user to input the required parameters for any three-dimensional figure.
The method should return the surface area and volume of that figure.

Strings/Quotes: Questions (8.) and (9.)
Find a quote from any of your favorite authors or your favorite quote.
If you do not have any favorite author or a favorite quote, make up a quote yourself, and indicate that it is your own quote.

(8.) Write a method that prints all the vowels in that quote, and returns the count.

(9.) Write a method that prints all the consonants in that quote, and returns the count.

(10.) Arithmetic:
Question (4.) on Page 165 of your textbook.

(11.) Acturial Science:
Question (9.) on Page 165 of your textbook.

(12.) Algebra:
Question (5.) on Page 165 of your textbook.

Java Programming Exercises, Practice, Solution by W3Resource
Please review:
Java Methods: Exercises, Practice, Solution
(https://www.w3resource.com/java-exercises/method/index.php)
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(13.) Write the Question as a comment in your program. Include the Title and the Question Number.
Write clear comments for each line of code in the Solution.
Run the program.
Submit clear screenshots.

For those who do not mind messing around with several languages at the same time
Student: Excuse me, Mr. C
This course is only for Java
What do you mean?
Teacher: You are correct.
But, these subsequent questions are not for everyone.
That is the reason I am putting them at the end.
I have a question for you.
Have you ever seen any IT/Computer Science position that requires the knowledge of only one programming language?
Student: I have not checked, Sir.
Teacher: If you intend to be in the IT/Programming field for the long run, at least four (four or more) languages are required.
If you look for IT positions at Indeed.com or other career/job websites, you will realize what I mean.
Search for java programmer, you might be surprised that even for entry level positions for a Java Programmer; they require you to have a working knowledge of several other programming languages.
Mr. C is preparing you for that...if you intend to work in the programming field for a long time.
Besides, this is a critical thinking approach.
I am required to develop and promote critical thinking questions for my students.
A programmer is basically a problem-solver irrespective of the programming language used to solve the problem.
Yes, we are working with Java. However, if you find out that C# would be better in solving a particular problem in your workplace, then you need to use C# unless your employer says otherwise.
The knowledge of several languages is a good asset. It makes you highly valuable.
Further, anyone who attempts any of the subsequent questions will still have to write the program in Java and get the same result.
The questions and solutions are in another language.
But the student will have to write the program in Java and come up with the same solution. So, we are still on track.
It is critical thinking...multiple approaches to solving a question.
Be it as it may, these subsequent questions are not required.
It is okay even if you do not look at them. 😊

C# Programming Exercises, Practice, Solution by W3Resource
Please review:
C# Function: Exercises, Practice, Solution
(https://www.w3resource.com/csharp-exercises/function/index.php)
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(14.) Write the Question as a comment in your program. Include the Title and the Question Number.
Write the program in Java
Run the program. Please make sure your program output is the same solution
Submit clear screenshots.

Some Substantive Responses

(1.) Review the post (Discuss Questions) done by your colleagues.
Use a different statement to work on the same method used by your colleague.
For example: if your colleague used an iteration statement in a function, you may use a conditional statement or a jump statement or a different iteration statement to write the same method to give the same output.

(2.) Review the post (Discuss Questions) done by your colleagues.
Use a different method to display the same output of the program done by your colleague.
For example: if your colleague used the Data type method, use the Void type method to write the program to display the same output.
You may include an appropriate message along with the output.

(3.) Review the post (Discuss Questions and Assess Questions) done by your colleagues.
If your colleague developed a console application for a program, develop a desktop application for the same program.
If your colleague developed a desktop application for a program, develop a console application for the same program.

(4.) Other substantive responses.

Check Your Understanding

Algebra: Questions (1.) and (2.)
Please review the Roots of a Quadratic Equation on the Expressions and Equations website: Quadratic Equations
(www.expressions-equations.appspot.com/#quadraticEquations)
There is a calculator I developed that calculates the roots of a quadratic equation and displays a message.

(I.) Write a method that requests the user to input the three values: (as seen on my calculator), and display the same message that is displayed by my calculator.
In other words, the output and message from your calculator should be the same as the output and message from my calculator when the user inputs those three values.
Test your program for each of the four cases of the discriminant regarding the nature of the roots of a quadratic equation as seen in Numbers $1a.$, $1b.$, $2.$ and $3.$ on my website.

(II.) Submit clear screenshots of your program.

(III.) Submit clear screenshots of the output of your program for the four cases.

(IV.) Submit clear screenshots of the output of my calculator for the four cases.

(III.) and (IV.) should display the same messages.

(1.) Console Application

(2.) Desktop Application

(3.) Geometry:
Question (8.) on Page 164 of your textbook.

(4.)

Vocabulary Words

array, list, ArrayList, single-dimensional array, one-dimensional array, dimension, rank, data structure, array type, array elements, square brackets, index, array index, array length, sort array, arrays as parameters, arrays as arguments, array methods, new keyword, Object keyword, tuple, ListBox, MultiLine TextBox, parallel arrays,

Objectives

Students will:

(1.) Discuss arrays.
(2.) Implement some array methods.
(3.) Pass arrays as function parameters.
(4.) Pass arrays as arguments.
(5.) Write programs that use arrays to solve real-world problems.

Recommended Readings

(1.) Textbook Chapter

(2.) Arrays: Part 1 by Oracle
(https://docs.oracle.com/javase/specs/jls/se7/html/jls-10.html)

(3.) Arrays: Part 2 by Oracle
(https://docs.oracle.com/javase/tutorial/java/nutsandbolts/arrays.html)

(4.) Arrays Class by Oracle
(https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/Arrays.html)

Videos:
Please click the RESOURCES tab of this website
Click the LinkedIn Learning (Kent State University) link
Follow the directions to access the website.
(5.) Type Java Array and/or Java Tuple in the search bar and view the results.

Videos and Textbooks:
Please click the RESOURCES tab of this website
Click the O'Reilly Online Learning link
Follow the directions to access the website.
(6.) Type Java Array and/or Java Tuple in the search bar and view the results.

(7.) Tuple Class by Oracle

(https://docs.oracle.com/middleware/11119/jdev/api-reference-esdk/oracle/javatools/util/Tuple.html)

(8.) Tuple Interface by Oracle

(https://docs.oracle.com/javaee/7/api/javax/persistence/Tuple.html)

Required Readings

Array

An Array is a list or data container that contains:
(1.) single or multiple values of the same data type or
(2.) multiple values of different data types

The dimension of an array is the direction in which one can specify the elements of the array.
Example:
Record the ages of the students in Mr C's class.
We have only one variable: age.
This is a one-dimensional array...array of integers
A one-dimensional array is also known as a single-dimensional array.

Each student in Mr. C's class takes at least one course this semester.
Record the number of courses taken by each student in Mr. C's class.
Some of the courses are one-credit, two-credit, three-credit, four-credit courses.
Assume the tuition for each course depends on the number of credit units.
Calculate the total cost of all the courses taken by all the students in Mr. C's class.
For us to do this, we need to list the number of courses taken by each student in Mr. C's class. We can represent this in the column.
We also need to calculate the cost of the courses taken by each student. We can represent this in the row.
So, we have two variables: courses and cost.
This is a two-dimensional array.
The column is the array of integers ... the number of courses.
The row is the array of doubles ... the cost of the number of courses taken by each student.
We can then find the total cost...connect this explanation with Matrices in Algebra
In this module, we are only concerned with one-dimensional array.

The rank of an array is the number of dimensions in the array.
This implies that the rank of a one-dimensional array is 1
The rank of a two-dimensional array is 2
The rank of a three-dimensioanl array is 3 and so on and so forth.

Why Are We Learning Arrays?
Assume you want to work with five different integers; rather than declare five different variables for the five integers, it is much better to declare a single integer array that will contain all five integers.

When we declare an array in Java:
(1.) We must declare the data type of the array.
(2.) We may or may not not indicate the size of the array.

Notable Notes About Arrays
(1.) An array is declared by specifying the data type of its elements.
You may or may not write the elements when you declare the array.
If the elements are of the same data type, then the array is declared by specifying that data type.
If the elements are of different data types, the the array is declared by specifying object as the data type.
When the elements are specified, they are enclosed in curly brackets or braces.

(2.) If the elements are of the same data type or of different data types, the var keyword can also be used.
The new keyword is used to specify the elements of an array if the array was declared without the elements.
Let us review several ways of declaring arrays.

                            // elements are not specified
                            // elements are the same data type
                            dataType[] arrayName; 

                            // elements are not specified
                            // elements are the same data type
                            // array size is specified
                            dataType[] arrayName = new dataType[arraySize]; 

                            // elements are specified, separated by comma   
                            // elements are the same data type
                            dataType[] arrayName = {array elements};

                            // elements are specified, separated by comma   
                            // elements are the same data type
                            // array size is specified
                            dataType[] arrayName = new dataType[arraySize] {array elements};

                            // elements are not specified
                            // elements are of different data types
                            object[] arrayName;

                            // elements are not specified
                            // elements are of different data types
                            // array size is specified
                            object[] arrayName = new object[arraySize]; 

                            // elements are specified, separated by comma
                            // elements are of different data types
                            Object[] arrayName = {array elements};

                            // elements are specified, separated by comma   
                            // elements are of different data types
                            // array size is specified
                            Object[] arrayName = new object[arraySize] {array elements};
                        

(3.) When an array is created, the number of dimensions and the length of each dimension are established.
Once the array instance is created, the number of dimensions and the length of each dimension cannot be changed during the lieftime of the instance.

(4.) Arrays are zero-indexed.
This implies that the position of array elements begin with zero.
The first element in the array is at position: zero or index: zero
The second array element is at index: one
The index of the third element in the array is two.
The index of the fourth array element is three.
Given an array of size: $n$; the index of the last element in the array is $n - 1$
We output the index of the array element by:
array[index] = element;

Example 1: Array of the perfect squares of the first positive ten integers
Declare an array of a specified size without the elements
Include elements in the array by using array index
Print the length/size of the array using the arrayName.length method
Print the array using the different types of iteration statements: for, while, do-while and foreach loops






Teacher: Remember we mentioned the foreach loop in Module 6
And we said we will implement it in Module 7
Do you like it?
Student: Yes I prefer it.
It seems easier than the other statements.
Teacher: Well, we shall be using it as we see fit.
Let us briefly discuss it.

ForEach Loop	For Loop, While Loop, Do-While Loop
(1.) Loops through each array element without using a counter.	(1.) Loops through each array element using a counter.
(2.) The length of the array is not needed.	(2.) The length of the array is needed.

Student: What if we want to keep adding elements to the array?
Teacher: Very good question.
In that case, we need to use an ArrayList
We shall cover ArrayList in details in the Advanced Java course.
However, let us review an example.

Example 2: Demonstrate the implementation of an ArrayList





Student: Mr. C
Why did you change the for-each loop?
That was not the way you used it in the first example.
I do not like the one you just used.
Teacher That is fine.
The approach I used is a functional operation for the for-each loop
But you may use the for-each loop that we used for the perfect squares.
This is what I did.
Initially, I used the for-each loop that we used in Example 1.
Then, I saw the light bulb warning by the side on the line.
I clicked it and clicked the option to use functional operation.
I do not like to see warnings in my code.
Hence, I used it.
Let us review more examples. Example 3: Create an array of strings of size 4
Print the array.
Print the fourth element of the array
Sort the array
Print the sorted array.
Print the fourth element of the sorted array.





Student: Mr. C
Just to be sure...
Because sometimes you declare several variables
And sometimes you use only variable
It can be confusing at times
So, the same variable that you used in the array and the sorted array: name
You used it because it was declared inside the loop?
So, it is only known within the loop? It is not known outside the loop...is that right?
Teacher: That is correct
Student: So, if I try to use that variable outside the loop, the program will not recognize it?
Teacher: That is correct
Student: But why did you not declare several variables like you did in the previous example?
Teacher: It is just a choice
You can declare several variables if you wish.

Let us do an input-output feature.
Let us also demonstrate the use of an array that stores values of different data types.

Example 4: Input-Output Feature for a Pizza Restaurant

Data Analysis: Descriptive Statistics with Java

Statistics comprises Data Analysis.
Data Analysis is part of Data Science.
Data Science is part of Computer Science/Programming.
As a programmer, it is very likely that you will deal with data.
In this course, we shall focus only on some of the Descriptive Statistics of Data Analysis.

The Descriptive Statistics that we shall discuss in this course are:

(1.) Measures of Center: Also known as the Measures of Central Tendency
They are the: Mean, Median, Mode, and Midrange.

(2.) Measures of Spread: Also known as the Measures of Dispersion or the Measures of Variability or the Measures of Variation
For this course, we shall focus on the: Range, Variance, and Standard Deviation.

(3.) Measures of Position: Also known as the Measures of Location
For this course, we shall focus on the: Five Number Summary of Data
They are the: Minimum, First Quartile, Second Quartile, Third Quartile, and Maximum.
The First Quartile is also known as the Lower Quartile or the 25th Percentile
The Second Quartile is also known as the Median or the Middle Quartile or 50th Percentile
The Third Quartile is also known as the Upper Quartile or 75th Percentile

Some Java packages have predefined methods used for calculating some of these measures.
We shall calculate the rest of the measures.
Let us write program examples of descriptive statistics using Java
The formulas used are the formulas on the Descriptive Statistics website
(1.) Formulas for the Measures of Center
(2.) Formulas for the Measures of Variation
(3.) Formulas for the Measures of Location

Example 5: Data Analysis: Descriptive Statistics of Raw Ungrouped Data with Java











Let us do an example that uses an Input-Output Feature
Ask the user how many numeric values that he/she would like to enter.
Store the values in an array.
In this case, it is better to write a method.
Write that a method that computes the descriptive statistics of the array.

Parallel Arrays

Some Substantive Posts

Textbook Questions
(1.) Question $(1.)$ on Page $409$

(2.) Question $(2.)$ on Page $409$

(3.) Question $(3.)$ on Page $409$

For Questions (4.) and (5.)
Please review these Sorting Techniques and Algorithms
(https://www.samdomforpeace.com/DataStructures/Sorting.html)

(4.) Write a method that sorts an array in ascending order using any of the techniques.
Use an array size of at least 3 (array size $\ge 3$).
Specify the technique.

(5.) Write a method that sorts an array in descending order using any of the techniques.
Use an array size of at least 3 (array size $\ge 3$).
Specify the technique.

(6.) Write a method that divides an even-sized unsorted array into two equal halves, sorts the first half in ascending order, and sorts the second half in descending order.
Use any even size of at least 8 (array size $\ge 8$).

(7.) Write a method that divides an even-sized unsorted array into two equal halves, sorts the first half in descending order, and sorts the second half in ascending order.
Use any even size of at least 8 (array size $\ge 8$).

For Question (8.)
Please review the: Arrays Class by Oracle
(https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/Arrays.html)
Scroll down till you see All Methods
(8.) Implement any two methods.

(9.) Please review the Solved Examples on the Measures of Center
Find any question that has a dataset that can be entered into an array.
(a.) Write a program that computes the measures of center for that question.
Test the program output with the results on the Descriptive Statistics Calculators
(b.) Solve the question.
Check your answer with the solution on the website.

(10.) Please review the Solved Examples on the Measures of Spread
Find any question that has a dataset that can be entered into an array.
(a.) Write a program that computes the measures of dispersion for that question.
Test the program output with the results on the Descriptive Statistics Calculators
(b.) Solve the question.
Check your answer with the solution on the website.

(11.) Please review the Solved Examples on the Measures of Position
Find any question that has a dataset that can be entered into an array.
(a.) Write a program that computes the measures of location for that question.
Test the program output with the results on the Descriptive Statistics Calculators
(b.) Solve the question.
Check your answer with the solution on the website.

(12.) Please review the Solved Examples on Descriptive Statistics
Find any question that has a dataset that can be entered into an array.
(a.) Write a program that computes the measures of center and/or the measures of variability and/or the measures of position for that question.
Test the program output with the results on the Descriptive Statistics Calculators
(b.) Solve the question.
Check your answer with the solution on the website.

Java Programming Exercises, Practice, Solution by W3Resource
Please review:
Java Array: Exercises, Practice, Solution
(https://www.w3resource.com/java-exercises/array/index.php)
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(13.) Write the Question as a comment in your program. Include the Title and the Question Number.
Write clear comments for each line of code in the Solution.
Run the program.
Submit clear screenshots.

For those who do not mind messing around with several languages at the same time
Student: Excuse me, Mr. C
This course is only for Java
What do you mean?
Teacher: You are correct.
But, these subsequent questions are not for everyone.
That is the reason I am putting them at the end.
I have a question for you.
Have you ever seen any IT/Computer Science position that requires the knowledge of only one programming language?
Student: I have not checked, Sir.
Teacher: If you intend to be in the IT/Programming field for the long run, at least four (four or more) languages are required.
If you look for IT positions at Indeed.com or other career/job websites, you will realize what I mean.
Search for java programmer, you might be surprised that even for entry level positions for a Java Programmer; they require you to have a working knowledge of several other programming languages.
Mr. C is preparing you for that...if you intend to work in the programming field for a long time.
Besides, this is a critical thinking approach.
I am required to develop and promote critical thinking questions for my students.
A programmer is basically a problem-solver irrespective of the programming language used to solve the problem.
Yes, we are working with Java. However, if you find out that C# would be better in solving a particular problem in your workplace, then you need to use C# unless your employer says otherwise.
The knowledge of several languages is a good asset. It makes you highly valuable.
Further, anyone who attempts any of the subsequent questions will still have to write the program in Java and get the same result.
The questions and solutions are in another language.
But the student will have to write the program in Java and come up with the same solution. So, we are still on track.
It is critical thinking...multiple approaches to solving a question.
Be it as it may, these subsequent questions are not required.
It is okay even if you do not look at them. 😊

C# Programming Exercises, Practice, Solution by W3Resource
Please review:
C# Array: Exercises, Practice, Solution
(https://www.w3resource.com/csharp-exercises/array/index.php)
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(14.) Write the Question as a comment in your program. Include the Title and the Question Number.
Write the program in Java
Run the program. Please make sure your program output is the same solution
Submit clear screenshots.

C++ Programming Exercises, Practice, Solution by W3Resource
Please review:
C++ Array: Exercises, Practice, Solution
(https://www.w3resource.com/cpp-exercises/array/index.php)
You are provided with the Questions and the Solutions.
No more than one student may do any specific question.

(15.) Write the Question as a comment in your program. Include the Title and the Question Number.
Write the program in Java
Run the program. Please make sure your program output is the same solution
Submit clear screenshots.

Some Substantive Responses

(1.) Review the post (Discuss Questions) done by your colleagues.
Use a different statement to work on the same Array or the same Tuple used by your colleague.
For example: if your colleague used an iteration statement in an array, you may use a conditional statement or a jump statement or a different iteration statement to write the same Array or the same Tuple to give the same output.

(2.) Review the post (Discuss Questions) done by your colleagues.
Use a different data structure to display the same output of the program done by your colleague.
For example: if your colleague used an Array, use a Tuple to write the program to display the same output.

(3.) Review the post (Discuss Questions and Assess Questions) done by your colleagues.
If your colleague developed a console application for a program, develop a desktop application for the same program.
If your colleague developed a desktop application for a program, develop a console application for the same program.

(4.) Review the post (Discuss Questions) done by your colleagues.
Use a different user-defined array method and/or system-defined array class method to work on the same program done by your colleague.

(5.) Other substantive responses.

Check Your Understanding

Textbook Questions
(1.) Question $(4.)$ on Page $409$

(2.) Question $(5.)$ on Pages $409$ and $410$

(3.) Please review Example 4: Input-Output Feature for a Pizza Restaurant
Please do these tasks.

(a.) Modify the application to include the name and slogan of the restaurant in the customer's receipt.
In other words, Lines #16 - 19 should be included in the customer's receipt on the condition that those lines should be written only one time in the project but called twice. Do you understand what I mean? We did that concept in Module 6
Submit the screenshots for the code and the output.

(b.) Samuel entered an order for a customer.
He noticed that the total cost for that customer was less than similar orders he gave past customers.
So, he reviewed his entries and noticed that he mistakenly entered "Extra cheese" rather than "extra cheese".
He did not realize that the application was data entry case-sensitive.
He met with his manager and asked her to reconsider the application.
The manager contacted you, the programmer; and informed you about the concern. Using at least five different sentences, address this issue.
Consider the fact that the manager is not a programmer.
Inform the manager of several options/applications and suggest the best option.
Asking the manager to ensure that all her employees are properly trained on case-sensitive data entry is not considered an option in this case.
Write your responses on the Blackboard Editor.
Cite your source(s) as applicable.

For Questions (4.) through (7.):
Please review the GUI Programming Examples.
(I.) User-defined methods are required.
(II.) Parallel arrays are required. One array should be for the data variable and the other array should be for the frequency.
(III.) You may use a pre-defined array (ListBox) or you may allow the user to enter the values (MultiLine TextBox)
(IV.) Desktop application is optional. You may develop a console application.
(V.) Multiple forms are optional.

(4.) Please review the Solved Examples on the Measures of Center
Find any question that has Ungrouped Data with frequency.
(a.) Write a program that computes the measures of center for that question.
Test the program output with the results on the Descriptive Statistics Calculators
(b.) Solve the question.
Check your answer with the solution on the website.

(5.) Please review the Solved Examples on the Measures of Spread
Find any question that has Ungrouped Data with frequency.
(a.) Write a program that computes the measures of dispersion for that question.
Test the program output with the results on the Descriptive Statistics Calculators
(b.) Solve the question.
Check your answer with the solution on the website.

(6.) Please review the Solved Examples on the Measures of Position
Find any question that has Ungrouped Data with frequency.
(a.) Write a program that computes the measures of location for that question.
Test the program output with the results on the Descriptive Statistics Calculators
(b.) Solve the question.
Check your answer with the solution on the website.

(7.) Please review the Solved Examples on Descriptive Statistics
Find any question that has Ungrouped Data with frequency.
(a.) Write a program that computes the measures of center and/or the measures of variability and/or the measures of position for that question.
Test the program output with the results on the Descriptive Statistics Calculators
(b.) Solve the question.
Check your answer with the solution on the website.

Vocabulary Words

Objectives

Students will:

(1.)
(2.)

Recommended Readings

(1.) Textbook Chapter

Videos:
Please click the RESOURCES tab of this website
Click the LinkedIn Learning (Kent State University) link
Follow the directions to access the website.
(4.) Type Java Multidimensional Array and/or Java Jagged Array in the search bar and view the results.

Videos and Textbooks:
Please click the RESOURCES tab of this website
Click the O'Reilly Online Learning link
Follow the directions to access the website.
(5.) Type Java Multidimensional Array and/or Java Jagged Array in the search bar and view the results.

Required Readings

Some Substantive Posts

(1.)

Some Substantive Responses

Check Your Understanding

(1.)

There are three options for your Final Exam
Please choose only one option.

Option 1 (Combo Option: Final Exam and Final Project)

This option is based on your textbook (MindTap course).
This implies that it is not free.
However, you have two-weeks free access. So, it is free if you can complete all the graded assessments in two weeks.

Please click the Gradebook and complete all the assessments there.
The assessments that are automatically graded count for the Final Exam.
The assessments that are to be manually graded count for the Final Project.

Access the MindTap Course
Course Key: MTPPC12Q2KTJ

Option 2 (Course Summary)

This exam is designed to assess your understanding of the beginning Java concepts.

You have reviewed several topics and several concepts in each topic for eight modules.
Pick at least $1$ concept in at least $1$ topic in each of the $8$ modules.
That gives at least $8$ concepts in $8$ different topics in $8$ modules.
Find two more concepts in any topic in any module.
That gives $10$ concepts.

For each concept, please:

(1.) Write at least three sentences about that concept.

(2.) Develop a program about that concept.
In other words, write at least one code example about the concept.
Run the code.
Display the output.
Submit clear screenshots of your program (code and output)

Deliverables:
(1.) 10 concepts in 10 different topics for 8 modules
Please write the: Module number, the Topic, and the Concept
(2.) Three sentences for each concept.
(3.) Code for each concept.
(4.) Output for each concept.

Please submit all these information as a zipped folder (.zip only) in the Final Exam folder of the Blackboard course.

Option 3: Introduction to Programming Using Java (98 - 388)

Candidates for this exam are application developers working with Java 6 SE or later, secondary and immediate post-secondary level students of software development, or entry-level software developers.
Candidates should have at least 150 hours or instruction or hands-on experience with Java, are familiar with its features and capabilities, and understand how to write, debug and maintain well-formed, well documented Java code.

Please review some of the questions and answers of the Microsoft Introduction to Programming Using Java Exam
(https://www.itexams.com/exam/98-388)
This is Free But Requires Patience
Focus on what we covered (Beginning Java).
However, you are welcome to review all of them and attempt the Advanced Java topics.

Student: Mr. C, you are giving us a final exam with the answers?
How nice of you?
Teacher: Yes of course, I am nice. 😊
But, please read on.

Please:
(1.) Review Past Questions and Answers
You may not do any of those questions because they have been done already.

(2.) Do not attempt any question already indicated by your colleague.
If your colleague indicates by writing that he/she is working on a question, then you need to find another question.
No two or more students are permitted to do the same question.

(3.) Pick any five questions.

(4.) Go to the Final Exam Questions forum of the Blackboard course.

(5.) Write the question numbers in that forum only if it has not been written by any other student.
In other words, you need to review any questions posted by your colleagues and make sure that you do not attempt the same question.

(6.) Explain the solutions of those five questions using your own explanations and your code examples.

(7.) Number the questions, the solutions, your code examples and output, and your explanations based on the actual question numbers.

(8.) Submit the actual questions, the corresponding numbered solutions, your corresponding numbered explanations and your corresponding code examples and output and any other relevant information in the Final Exam folder of the Blackboard course.

(9.) Make your work easy for me to grade.
In other words, write detailed clear specific explanations.
Do not give me any avenue to deduct points.

Option 4: Advanced Placement (AP) Computer Science Exam

This exam is designed to assess your understanding of the Java language.

Please review all the questions and answers of the Advanced Placement (AP) Computer Science Exams

Student: Mr. C, you are giving us a final exam with the answers?
How nice of you?
Teacher: Yes of course, I am nice. 😊
But, please read on.

Please:
(1.) Review Past Questions and Answers
You may not do any of those questions because they have been done already.

(2.) Do not attempt any question already indicated by your colleague.
If your colleague indicates by writing that he/she is working on a question, then you need to find another question.
No two or more students are permitted to do the same question.

(3.) Pick any five questions.

(4.) Go to the Final Exam Questions forum of the Blackboard course.

(5.) Write the question numbers in that forum only if it has not been written by any other student.
In other words, you need to review any questions posted by your colleagues and make sure that you do not attempt the same question.

(6.) Explain the solutions of those five questions using your own explanations and your code examples.

(7.) Number the questions, the solutions, your code examples and output, and your explanations based on the actual question numbers.

(8.) Submit the actual questions, the corresponding numbered solutions, your corresponding numbered explanations and your corresponding code examples and output and any other relevant information in the Final Exam folder of the Blackboard course.

(9.) Make your work easy for me to grade.
In other words, write detailed clear specific explanations.
Do not give me any avenue to deduct points.

For example:
First Task: Notify your colleagues of the questions you intend to do.
In the Final Exam Questions forum of the Blackboard course: you may write:
Hey guys, I am doing $2006$ Question ($2$.), $2010$ Question ($3$.), ... etc.

Second Task: Do the questions.
(1.) $2006$ Question (2.)
Write the question or take screenshots of the question.
Develop the Java program. Write detailed comments.
Run the program.
Submit clear screenshots of the code and results.

(2.) $2010$ Question (3.)
Write the question or take screenshots of the question.
Develop the Java program. Write detailed comments.
Run the program.
Submit clear screenshots of the code and results.

Third Task: Submit all deliverables.
Submit clear screenshots of the: actual questions, the Java program (including comments) of the solutions, and the results of the five questions in the Final Exam folder of the Blackboard course.

Should you have any questions, please let me know.

Thank you.