What is Java

Introduction

Java is a popular programming language used to create software that can run on many devices. It helps programmers write code once and run it anywhere.

When you want to build mobile apps for Android phones.

When creating large business applications that need to be reliable.

When developing games or desktop software that works on different computers.

When writing programs that run on servers to handle websites or online services.

Syntax

Java

public class ClassName {
    public static void main(String[] args) {
        // Your code here
    }
}

This is the basic structure of a Java program.

The main method is where the program starts running.

Examples

This program prints "Hello, world!" to the screen.

Java

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, world!");
    }
}

This program adds two numbers and shows the result.

Java

public class AddNumbers {
    public static void main(String[] args) {
        int a = 5;
        int b = 3;
        int sum = a + b;
        System.out.println("Sum is: " + sum);
    }
}

Sample Program

This simple program prints a welcome message to the screen.

Java

public class Welcome {
    public static void main(String[] args) {
        System.out.println("Welcome to Java programming!");
    }
}

Important Notes

Java code needs to be compiled before it can run.

Java programs run inside a special environment called the Java Virtual Machine (JVM).

Summary

Java is a language used to write programs that work on many devices.

It uses a special structure with a main method to start running.

Java programs are compiled and run inside the JVM.