Writing Your First Java Program

Java is a widely used programming language, known for its simplicity, portability, and robustness. Writing your first Java program is an exciting step in learning to code. Here’s a step-by-step guide:

Create a Java Program File

1. Open your text editor or IDE.

2. Create a new file named HelloWorld.java. The file name must match the class name (case-sensitive) to avoid compilation errors.


// This is a simple Java program
public class HelloWorld {
    public static void main(String[] args) {
        // Print a message to the console
        System.out.println("Hello, World!");
    }
}

Explanation:

public class HelloWorld: Defines a public class named HelloWorld.

public static void main(String[] args): The entry point of the program.

System.out.println(“Hello, World!”);: Prints “Hello, World!” to the console.

Compile the Program

1. Open a terminal or command prompt.

2. Navigate to the directory where you saved HelloWorld.java

3. Run the following command to compile the program:


javac HelloWorld.java

4. If there are no errors, this will generate a file named HelloWorld.class.

Run the Program

1. In the same directory, execute the following command:


java HelloWorld

2. You should see the output


Hello, World!