Many Comments

Comments can be placed after a program statement to explain what it does, as here:

class Haiku
{
  public static void main ( String[] args )
  {
    System.out.println("On a withered branch" );  // Write first line of the poem
    System.out.println("A crow has just alighted:");  // Write 2nd line of the poem
    System.out.println("Nightfall in autumn.");  // Write 3rd line of the poem
  }
}

As with all comments, the "//" and everything after it on that line are ignored by the compiler. The program statement in the start of the line is not affected by the comment.