Writing and Running Your First Java Program: A Beginner’s Guide

Java is one of the most popular programming languages in the world. It's known for its portability, object-oriented structure, and wide usage in enterprise applications. If you're just getting started, writing your first Java program is a great step toward becoming a developer.

This guide will walk you through installing Java, writing a simple program, and running it.

Step 1: Install Java Development Kit (JDK)

Before you can write Java code, you need the Java Development Kit (JDK) installed.

 How to Install JDK:

1. Go to https://www.oracle.com/java/technologies/javase-downloads.html

2. Download and install the latest JDK version for your operating system.

3. Verify installation:

java -version
javac -version

Step 2: Set Up Your Development Environment

You can use any text editor or an Integrated Development Environment (IDE) like:

• VS Code

• IntelliJ IDEA

• Eclipse

For beginners, VS Code or IntelliJ IDEA is recommended.

Step 3: Write Your First Java Program

Open your editor and create a file named HelloWorld.java. Then, type the following code:

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

 Explanation:

• public class HelloWorld: Defines a class named HelloWorld.

• main(String[] args): The entry point of any Java application.

• System.out.println: Prints text to the console.

Step 4: Compile the Java Program

Use the terminal or command prompt to compile the file:

javac HelloWorld.java

If there are no errors, it creates a HelloWorld.class file (bytecode).

Step 5: Run the Java Program

Execute the program with:

java HelloWorld

Output:

Hello, World!

Bonus Tip: Common Mistakes to Avoid

• File name and class name should match.

• Java is case-sensitive.

• Don't forget the semicolon at the end of statements.

What’s Next?

Now that you've written your first Java program, explore:

• Variables and data types

• Control flow (if, switch, loops)

• Object-Oriented Programming (OOP) basics

• Java packages and modules

Conclusion

Writing and running your first Java program is the foundation of your programming journey. Java is a robust, scalable language that powers everything from Android apps to enterprise systems.

Keep practicing, and soon you'll be building more advanced applications with confidence!