← Back to Chapters

Java Introduction

☕ Java Introduction

? Quick Overview

Java is a high-level, object-oriented programming language developed by Sun Microsystems. It is widely used for building desktop applications, web applications, mobile apps, and enterprise systems. Java follows the principle of Write Once, Run Anywhere.

? Key Concepts

  • Object-Oriented Programming (OOP)
  • Platform Independent
  • Strongly Typed Language
  • Automatic Memory Management
  • Rich Standard Library

? Syntax & Theory

Java programs are written using classes and methods. Every Java program must have at least one class and a main method.

? View Code Example
// Basic structure of a Java program
class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, Java!");
    }
}

?️ Live Output / Explanation

Output

Hello, Java!

The System.out.println statement prints text to the console. The program execution starts from the main method.

? Interactive Playground: Variables

Enter values below to simulate how Java handles basic variables and output.

> System ready...
> Waiting for input...

? Tips & Best Practices

  • Always match class name with file name
  • Use meaningful class and variable names
  • Follow proper indentation and formatting
  • End statements with semicolons

? Try It Yourself

  • Change the output message and run the program
  • Create a program to print your name
  • Add comments explaining each line