A good answer might be:

An ordinary Button could be used.

An ordinary Button (a Button object of the Button class) generates actionEvents and needs an ActionListener that implements actionPerformed(). The actionPerformed() method can call System.exit( 0 ) to exit the program. Let us write a program that:

• has a frame that contains one Button.
  • The frame will be a listener for the button.
  • The frame will implement ActionListener.
• Clicking on the Button will exit the program.
  • The actionPerformed() method will call System.exit( 0 ).
• Clicking on the "close button" of the frame will do nothing.
  • This program will not have a listener for window events.

Often a real application will have several ways to quit: the close window button, a menu selection, and perhaps a Button like this program.

QUESTION 14: