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👋 Hello World in Java

Let’s write your first Java program — the famous "Hello, World!"

💡 What Is It?​

“Hello World” is the traditional first program in any language. It teaches:

  • How to write code
  • How to compile Java
  • How to run Java

☕ Fun Fact​

The first “Hello, World” in programming was written by Brian Kernighan in 1972 — even before Java was born!

🧒 Explain Like I'm Five​

Think of Java like a letter you write, but your computer can’t read it directly. You need to translate (compile) it and then deliver (run) it. This Hello program is like your first “Hi!” to the computer. 😊

🏗️ Code Example​

1. Create a file named HelloWorld.java​

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

2. Compile the code​

javac HelloWorld.java

If successful, a HelloWorld.class file will be created.

3. Run the compiled file​

java HelloWorld

✅ You should see:

Hello, World!

🔍 Breakdown of the Code​

Code PartWhat it Means
public class HelloWorldDeclares a class (every Java program is inside a class)
public static void main(String[] args)Entry point — the first thing Java runs
System.out.println(...)Prints to console

🔁 Real-World Analogy​

Writing a Java program is like making a cake:

  • You write a recipe (Java code)
  • You compile it with a chef (compiler)
  • You serve the cake (run the output)

📝 Try It Yourself​

🧪 Exercise​

  1. Create a new file: HelloWorld.java
  2. Paste this code:
public class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello, Java Learner!");
  }
}
  1. Compile and run:
javac HelloWorld.java
java HelloWorld

✅ Output should be:

Hello, Java Learner!

Write your output here: ____________

🚀 What's Next?​

Now that you've made Java speak, it's time to learn about Java Syntax and how Java programs are structured.