Introduction to Java

 

What is Java?

Java is a programming language used to create different types of software like:

Mobile applications (Android apps)

Web applications

Desktop software

Games

Banking and enterprise applications

Java was created by James Gosling in 1995.

It is one of the most popular and trusted programming languages in the world 🌍.

Why Java is Popular?

Java is popular because:

✅ Easy to learn for beginners

✅ Works on many devices

✅ Secure and reliable

✅ Used in real-world applications like banking, shopping apps, and websites

Java is Platform Independent

Java follows the rule:

“Write Once, Run Anywhere”

This means:

You write Java code once

It can run on Windows, Linux, or Mac without changes

This is possible because Java uses JVM (Java Virtual Machine).

How Java Works? (Simple Explanation)

You write Java code (.java file)

Java compiler converts it into bytecode

JVM runs this bytecode on any system

So Java does not depend on the operating system 👍

Basic Structure of a Java Program

Let’s see a simple Java program:

Copy code

Java

class HelloWorld {

    public static void main(String[] args) {

        System.out.println("Hello, Java!");

    }

}

Explanation of the Code (Line by Line)

1. class HelloWorld

A class is a container that holds code

HelloWorld is the class name

Class name should start with a capital letter

2. public static void main(String[] args)

This is the main method

Java program starts running from here

Without the main method, Java program will not run

3. System.out.println("Hello, Java!");

Used to print output on the screen

Whatever is inside quotes " " will be displayed

Output:

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Hello, Java!

Basic Java Syntax Rules

Java is case-sensitive

Main and main are different

Every statement ends with semicolon (;)

Code must be written inside a class

Main method is compulsory

Features of Java (Easy Words)

Simple – Easy to understand

Object-Oriented – Code is written using objects

Secure – Safe from viruses

Portable – Runs anywhere

Robust – Handles errors well

Where Java is Used?

Android apps 📱

Banking systems 🏦

E-commerce websites 🛒

Enterprise software 🏢

Games and tools 🎮

Conclusion

Java is a powerful and beginner-friendly language.

It is widely used in the software industry and is a great choice to start your programming journey 🚀.