A good answer might be:

The only problem is coordinating the command the button sends with what the listener does.

Corrected actionPerformed()

Here is the complete program: 

import java.awt.*; 
import java.awt.event.*;

public class TwoButtons extends Frame implements ActionListener
{
  Button redButton = new Button("Red");
  Button grnButton = new Button("Green");

  TwoButtons()                              // constructor for TwoButtons
  {  
     setLayout( new FlowLayout() );         // choose the layout manager 
     redButton.addActionListener( this );   // the buttonDemo object is 
     grnButton.addActionListener( this );   // the listener for each Button. 
    
     redButton.setActionCommand( "red" );   // set the red button's command 
     grnButton.setActionCommand( "green" ); // set the green button's command   

     add( redButton );                      // add the buttons to the container
     add( grnButton );                      
  }

  public void actionPerformed( ActionEvent evt)
  {
                                            // check which command has been sent
    if ( evt.getActionCommand().equals( "red" ) )
      setBackground( Color.red );    
    else 
      setBackground( Color.green );    

    repaint();                             // ask the system to paint the screen.
  }

  public static void main ( String[] args )
  {
    TwoButtons demo  = new TwoButtons() ;
    
    WindowQuitter wquit = new WindowQuitter(); 
    demo.addWindowListener( wquit );
    
    demo.setSize( 200, 150 );     
    demo.setVisible( true );      

  }
}

class  WindowQuitter  extends WindowAdapter 
{
  public void windowClosing( WindowEvent e )
  {
    System.exit( 0 );  // what to do for this event--exit the program
  }
}

Of course, you will copy it and run it. It is the basis of the programming exercises for this chapter.

QUESTION 15:

When the program is running, does it matter in which order the buttons are clicked?

Click Here after you have answered the question