Your First Java Program: Practice with the Bare Bones

• Using NetBeans or a text editor of your choice, type or copy-paste the following:

 // The public static void main method for running from a command line
 // String args[] is a String array that contains the command line arguments.
 public static void main(String args[]) {

  // Define a variable called message, put some default text in it.
  String message = "Hello world, this is Java I!";
 
  // Print that to the output window
  System.out.println(message);

 // Close the method.
 }

// Close the class.
}
 

• If you used NetBeans or a similar IDE...
• Under the Filesystems tab in the upper left, look for the file you created.
• Right-click on that file and choose 'Execute'.  That command will save and compile your file, and then attempt to run it.
• If compilation fails, the program will not execute.  Instead, it will display the compilation errors at the output window toward the bottom of your screen.
  
• If you used a text editor...
  
• Save the file as HelloWorld.java
• Go to a command prompt.  How?
• Go to the directory where you saved HelloWorld.java, and type javac HelloWorld.java
• Then, type Java HelloWorld
• If all works well, it should print out a welcome message.  If not, let me know.

Created by:  Brandan Jones December 17, 2001
Updated September 28, 2004