CheckerBoard Java Swing Example

 import java.awt.*; 
 import javax.swing.*; 
 public class CheckerBoardJavaExample extends JFrame 
   { 
       private final int ROWS = 8; 
       private final int COLS = 8; 
       private final int GAP = 2; 
       private final int NUM = ROWS * COLS; 
       private int x; 
       private JPanel pnl = new JPanel 
       (new GridLayout(8,8,2,2)); 
       private JPanel[] pnl1 = new JPanel[NUM]; 
       private Color clr = Color.WHITE; 
       private Color clr2 = Color.BLUE; 
       private Color tColor; 
       public CheckerBoardJavaExample() 
          { 
              super("CheckerBoard in Java Swing"); 
              setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
              add(pnl); 
                for(x = 0; x < NUM; ++x) 
                     { 
                         pnl1[x] = new JPanel(); 
                         pnl.add(pnl1[x]); 
                         if(x % COLS == 0) 
                            { 
                               tColor = clr; 
                               clr = clr2; 
                               clr2 = tColor; 
                            } 
                               if(x % 2 == 0) 
                               pnl1[x].setBackground(clr); 
                               else 
                               pnl1[x].setBackground(clr2); 
                      } 
           } 
                     public static void main(String[] args) 
                       { 
                            CheckerBoardJavaExample CheckerBoard = new CheckerBoardJavaExample(); 
                            final int SIZE = 300; 
                            CheckerBoard.setSize(SIZE, SIZE); 
                            CheckerBoard.setVisible(true); 
                       } 
   }