JAVA series

This set of Java series is for you If you have any questions or are unable to grasp a concept, the series provides practice sets that will help you improve your java skills.

 

Introduction to JAVA

JAVA is an Object Oriented Programming language Developed by Sum Micro-system of USA in 1991.

JAVA is a purely Object Oriented programing language Originally called “OAK” by the Inventor of Java (James Gerlin). it was created in the year 1991 in USA.

 

How Java Works

 

JAVA is compiled into the bytecode and then it is interpreted to machine code.

Source Code —> Byte Code —> Machine Code

 

Java Installation

• check out my article on how to set up vsCode ( an IDE )for Java link
• Also check out my article on how to create a java project in vscode

Optionally you can choose to use any IDE of your choice

• JDK – JAVA Development Kit Collection of tools used for developing and running JAVA program
• JRE – JAVA Runtime Environment Help in executing program developed in JAVA
• Package - A package in JAVA is used to group relative classes . Think of it’s a folder in a file directory

 

Basic Structure of a JAVA program

When the JVM start, it looks for a class you give it at the command line, then it start looking specifically for a method in your program that looks exactly like this

 

Public static void main (String [ ] args ){ 
//System.out.println( “Hello World” )
};

 

• Next the JVM runs everything between the curly brace { } of your main method
• Every Java application has at least one class and a main method(not one main method by class, but just one main method per application)

 

 

1. Method: A method is a block of code which only runs when it is called. You can pass data, known as parameters, into a method. Methods are used to perform certain actions, and they are also known as functions. 

 

2. Classes:Classes Everything in Java is associated with classes and objects, along with its attributes and methods. For example: in real life, a car is an object. The car has attributes, such as weight and color, and methods, such as drive and brake.

 

What are Strings and Variable ?

• String: any word or number written in between a hyphen
• Variable: any form of representation that holds a value

 

Naming Convention

For Variable we use Pascal Convention or Case Convention

Normal – Add two number(wrong) Pascal – AddTwoNumber(correct)

Camel – addTwoNumber(correct)

 

• For Classes we use Pascal Convention

Normal – Add two number(wrong) Pascal – AddTwoNumber(correct)

 

• For method/functions we use camel Case Convention

Camel – addTwoNumber

 

Comments in Java

 

There are three types of comments in Java.

i. Single line Comment

// System.out.println("Sample!");

ii. Multi-line Comment

/*
    System.out.println("Sample!");
    System.out.println("Alice!");
*/

iii. Documentation Comment. Also called a doc comment.

/** documentation */

 

Next → Variable and Data Types and Strings in JAVA 

 

All Concepts

1.Variable and Data Types and Strings in JAVA 

2.Operators in JAVA

3.Condition in JAVA 

4.Loop Control in JAVA 

5.Arrays in JAVA (coming soon) 6.Methods in JAVA

7.Introduction to OOPS ( important ),(coming soon)

8.Access Modifier & Constructor (coming soon)

9.Inheritance in JAVA (coming soon)

10.Abstract Classes & Interface (coming soon)

11.Package in JAVA (coming soon)

12.Multithreading in JAVA (coming soon)

13.Error & Exception (coming soon)

14.Advance JAVA – I (coming soon)

15.Advance JAVA – II(coming soon)