Hello, World!

It’s time to write your first Java program! Here is a step-by-step guide on how to write your program in different ways.

Option 1: Using IntelliJ IDEA

Create a New Project

• On the welcome screen, click New Project.
• In the new project window:
  • Select Java from the project templates.
  • Make sure your JDK is selected (If not, click Add JDK and locate the JDK installation path).
  • Click Next.

Configure the Project

• Project Name: Enter a name for your project (e.g., HelloWorld).
• Project Location: Choose a folder where the project will be saved.
• Click Finish.

Create a New Java Class

• In the Project window on the left, expand the src directory.
• Right-click on src, select New > Java Class.
• In the pop-up window, name the class (e.g., HelloWorld) and click OK.

Write Your Java Code

• IntelliJ will open the newly created class file.
• Write the following code in the HelloWorld.java file:

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

Run the Program

• To run your program, click the Run button (a green triangle) in the top toolbar or right-click the class file and select Run ‘HelloWorld’.
• You should see Hello, World! printed in the console at the bottom of the screen.

Option 2: Using Eclipse

Create a New Java Project

• In the Eclipse main window, go to File > New > Java Project.
• In the new project window:
  • Project Name: Enter the name of your project (e.g., HelloWorld).
  • Click Finish to create the project.

Create a New Java Class

• In the Project Explorer on the left, expand your project folder.
• Right-click the src folder, then select New > Class.
• In the new class window:
  • Name: Enter the class name (e.g., HelloWorld).
  • Check the box to include the public static void main(String[] args) method.
  • Click Finish.

Write Your Java Code

• The newly created class will open in the editor.
• If the main method is not automatically generated, write the following code:

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

Run the Program

• Click the Run button (green circle with a white triangle) in the toolbar or right-click on the class file and select Run As > Java Application.
• The console at the bottom will display Hello, World!.

Option 3: Terminal / Command Prompt

Open Terminal or Command Prompt

• Windows: Open Command Prompt (type cmd in the Start menu).
• macOS/Linux: Open the Terminal application.

Create a Java File

• Navigate to the directory where you want to save your Java file. For example, you can create a folder named java_projects:

mkdir java_projects
cd java_projects

• Use a text editor to create the Java file. For example, you can use nano (Linux/macOS) or notepad (Windows):

nano HelloWorld.java

notepad HelloWorld.java

• In the text editor, write the following code:

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

Save the file and exit the editor:

• nano: Press CTRL + X, then Y to confirm and Enter to save.
• notepad: Simply save and close the file.

Compile the Java Program

• In the terminal, compile the Java program using the javac command:

javac HelloWorld.java

• If the compilation is successful, no output will appear, but a HelloWorld.class file will be generated in the directory.

Run the Java Program

• Run the compiled program using the java command:

java HelloWorld

• You should see the following output in the terminal:

Hello, World!