Java Programming Masterclass covering Java 11 & Java 17

Learn Java In This Course And Become a Computer Programmer. Obtain valuable Core Java Skills And Java Certification Instructor: Tim Buchalka
Course Repository:
Course Link: https://udemy.com/course/java-the-complete-java-developer-course/

What you'll learn

• Learn the core Java skills needed to apply for Java developer positions in just 14 hours.
• Be able to demonstrate your understanding of Java to future employers.
• Acquire essential java basics for transitioning to the Spring Framework, Java EE, Android development and more.
• Be able to sit for and pass the Oracle Java Certificate exam if you choose.
• Learn industry "best practices" in Java software development from a professional Java developer who has worked in the language for 18 years.
• Obtain proficiency in Java 8 and Java 11.

Course content

25 sections • 401 lectures • 80h 23m total length

• Course Introduction
• Software Tools Setup
• First Steps
• Java Tutorial: Expressions, Statements, Code blocks, Methods and more
• Control Flow Statements
• OOP Part 1 - Classes, Constructors, and Inheritance
• OOP Part 2 - Composition, Encapsulation, and Polymorphism
• Arrays, Java inbuilt Lists, Autoboxing and Unboxing
• Inner and Abstract Classes & Interfaces
• Java Generics
• Naming Conventions and Packages. static and final keywords
• Java Collections
• JavaFX
• Basic Input & Output including java.util
• Concurrency in Java
• Lambda Expressions
• Regular Expressions
• Debugging and Unit Testing
• Databases
• Java Networking Programming
• Java 9 Module System
• Migrating Java Projects to Java 9
• Course Remaster in Progress
• Archived Videos
• Extra Information - Source code, and other stuff

Section 1: Course Introduction

Section 2: Software Tools Setup

1. Java Development Kit Installation Overview

Choosing The Right JDK Vendor and JVM:
https://www.youtube.com/watch?v=zf-GOkc3Ht8

Java Development Kit: What Version of the JDK Should You Use?:
https://www.youtube.com/watch?v=HqU0TF4XNbM

2. Install JDK 11 for Windows

Amazon Corretto 11:
https://docs.aws.amazon.com/corretto/latest/corretto-11-ug/downloads-list.html java --version

3. Run Java in VSCode

https://www.youtube.com/watch?v=OhofTsLJc8Q

1. Install: Extension Pack for Java VSCode
2. ctrl + shift + p
3. Search for: Create Java Project
4. Select: No Build Tools
5. Select or Create a project folder
6. Type project name "HelloWorld"
7. Open the src/App.java file
8. Click save it will download and IntelliCode models
9. Click on RUN
10. Open the Console and see the output

Section 3: First Steps

1. Primitive Types

The eight primitive data types in Java are boolean, byte, char, short, int, long, float and double. Consider these types as the building blocks of data manipulation.

2. The char and boolean Primitive Data

A char occupies two bytes of memory, or 16 bits and thus has a width of 16. The reason it's not just a single byte is taht it allows you store Unicode characters.

Unicode is an international encoding standard for use with different languages and scripts, by which each letter, digit, or symbol is assigned a unique numeric value that applies across different platforms and programs

https://unicode-table.com/en/

A boolean value allows for two choices True or False, Yes or No, 1 or 0. In Java terms we have a boolean primitive type and it can be set to two values only. true or false. They are actually pretty useful and you will use them a lot when programming

3. Primitive Types Recap and the String Data Type

The String is a datatype in Java, which is not a primitve type. It's actually a Class, but it enjoys a bit of favoritism in Java to make it easier to use than a regular class.

• What is a String?: A String is a sequence of characters. In the case of the char, it could contain a single character only(regular character or Unicode character).

A String can contain a sequence of characters. A large number of characters. Technically it's limited by memory or the MAX_VALUE of an int which was 2.14 Billion. That's a lot of characters.

Strings in Java are immutable. Tah means you can't change a String after it's created. Instead, what happens is a new String is created.

4. Ternary Operator

int ageOfClient = 20; boolean isEighteenOrOver = ageOfClient == 20 ? true : false;

Operand one - ageOfClient == 20; in this case is the condition we are checking. It needs to return true or false

Operand two - true here is the value to assign to the variable isEighteenOrOver if the condition above is true

Operand three - false here is the value to assign to the variable isEighteenOrOver if the condition above was false

It can be a good idea to use parentheses like this to make the code more readable

boolean is EighteenOrOver = (ageOfClient == 20) ? true : false

5. Operator Precedence and Operator Challenge

Summary of Operators:
https://docs.oracle.com/javase/tutorial/java/nutsandbolts/opsummary.html

Java Operator Precedence Table:
http://www.cs.bilkent.edu.tr/~guvenir/courses/CS101/op_precedence.html

Section 4: Java Tutorial: Expressions, Statements, Code blocks, Methods and more

1. Keywords And Expressions

List of Java keywords:
https://en.wikipedia.org/wiki/List_of_Java_keywords

2. Method Overloading

• Method overloading is a feature that allows us to have more than one method with the same name, so long as we use different parameters.
• It is the ability to create multiple methods of the same name with different implementations.
• Calls to an overloaded method will run a specific implementation of that method.
• Same name easier to remember

public static int sum (int a, int b) {
  return a + b;
}
public static int sum (int a, int b, int c) {
  return a + b + c;
}
public static int sum (int a, int b, int c, int d) {
  return a + b + c + d;
}

Section 5: Control Flow Statements

1. The While, Do While break and continue Recap

• The while loop checks the condition at the start before executing the block.

• With the do while loop the code block is executed at least once and then the condition is checked.

• Be careful with conditions, it is easy to end up with endless loop in other words a loop that never ends or to end up with loop that never executes.

• Tip: always check your conditions/expressions.

• We can interrupt the loop by using a continue and/or a break statement.

• With the continue keyword the loop will bypass the part of code block that is below the continue keyword and continue with the next iteration.

• With the break keyword we can exit the loop depending on the condition that we are checking.

Section 6: OOP Part 1 - Classes, Constructors, and Inheritance

1. Method Overloading vs Overriding Recap

Method Overloading

• provides functionality to reuse a method name with different parameters.
• Usually in a single class but may also be used in a child class.
• Must have different parameters.
• May have different return types.
• May have different access modifiers (private, protected, public).
• May throw different exceptions.

Method Overriding

• Used to override a behavior which the class has inherited from the parent class.
• Always in two classes that have a child-parent or IS-A relationship.
• Must have the same parameters and same name.
• Must have the same return type or covariant return type (child class).
• Must NOT have a lower modifier but may have a higher modifier.
• Must NOT throw a new or broader checked exception.

2. Static vs Instance Methods

• Static methods are declared using a static modifier.

• Static methods can't access instance methods and instance variables directly.

• They are usually used for operations that don't require any data from an instance of the class (from 'this').

• If you remember, the this keyword is the current instance of a class.

• In static methods we can't use the this keyword.

• Whenever you see a method that does not use instance variables that method should be declared as a static method.

• For example main is a static method and it is called by the JVM when it starts an application

• Instance Methods belong to an instance of a class.

• To use an instance method we have to instantiate the class first usually by using the new keyword.

• Instance methods can access instance methods and instance variables directly.

• Instance methods can also access static methods and static variables directly.

Should a method be static? Does it use any fields (instance variables) or instance methods? Yes: It should probably be an instance method No: It should probably be a static method

3. Static vs Instance Variables

• Declared by using the keyword static.
• Static variables are also known as static member variables.
• Every instance of that class shares the same static variable**
• If changes are made to that variable, all other instances will see the effect of the change.
• Static variables are not used very often but can sometimes be very useful.
• For example when reading user input using Scanner we will declare scanner as a static variable.
• That way static methods can access it directly.
• The don't use the static keyword.
• Instance variables are also known as fields or member variables.
• Instance variables belong to an instance of a class.
• Every instance has it's own copy of an instance variable.
• Every instance can have a different value (state).
• Instance variables represent the state of an instance.

Section 7: OOP Part 2 - Composition, Encapsulation, and Polymorphism

Section 8: Arrays, Java inbuilt Lists, Autoboxing and Unboxing

1. Arrays Recap

• An array is a data structure that allows you to store multiple values of the same type into a single variable.
• The default values of numeric array elements are set to zero.
• Arrays are zero indexed: an array with n elements is indexed from 0 to n-1, for example 10 elements index range is from 0 to 9.
• If we try to access index that is out of range Java will give us an ArrayIndexOutOfBoundsException, which indicates that the index if out of a range in other words out of bounds.
• To access array elements we use the square braces [ and ], also known as array access operator.

Example of creating a new array
int[] array = new int[5];

• This array contains the elements from array[0] to array[4].
• It has 5 elements and index range 0 to 4.
• The new operator or keyword is used to create the array and initialize the array elements to their default values.
• In this example, all the array, all the array elements are initialized to zero since this is an int array.
• For boolean array elements they would be initialized to false.
• For string or other objects that would be null, but we will talk more about null and what it is later in the course.

int[] myNumbers = {5, 4, 3, 2, 1};

• We can also initiliaze an array inline by using array initializer block { and }. Values we defined need to be separated by a comma.
• This way of initializing an array is also known as an anonymous array.
• It has 5 elements and index range 0 to 4.
• In this example, array elements are initialized to 5, 4, 3, 2, 1.