hierarchyrelationshiptest1.java

《Java面向对象程序设计》例子源代码.轻松学习书本.

//HierarchyRelationshipTest1.java
import javax.swing.JOptionPane;
public class HierarchyRelationshipTest1 { 
   public static void main( String[] args ) 
   {
      Point3 point = new Point3( 30, 50 );                      
      Circle3 circle = new Circle3( 120, 89, 2.7 );         
      String output = "Call Point3's toString with superclass" +
         " reference to superclass object: \n" + point.toString();
      output += "\n\nCall Circle3's toString with subclass" +
         " reference to subclass object: \n" + circle.toString();
      Point3 pointRef = circle; 
      output += "\n\nCall Circle3's toString with superclass" +
         " reference to subclass object: \n" + pointRef.toString();
      JOptionPane.showMessageDialog( null, output );  
      System.exit( 0 );
   } 
}