// Outputs "Hello, world!" and then exits
public class HelloWorld {
   public static void main(String[] args) {
       System.out.println("Hello, world!");
   }
}

// This is an example of a single line comment using two slashes
 
/* This is an example of a multiple line comment using the slash and asterisk.
   This type of comment can be used to hold a lot of information or deactivate
   code but it is very important to remember to close the comment. */
 
/** 
 * This is an example of a Javadoc comment; Javadoc can compile documentation
 *  from this text. 
 */