resultdemo.java

这是《Java 2 简明教程(第2版)》一书配套的源代码。

import java.awt.Graphics;
import java.applet.Applet;

class A
{
  public int x,y;
  A(int a,int b)
   {
       x=a;
       y=b;  
    }

  public void display()
   {int z;
    z=x+y;
    System.out.println("add="+z);
    }
}

class B extends A
{
    B(int a,int b)
    {
      super(a,b);
    }   

    public void display()
    {int z;
     z=x*y;
     System.out.println("product="+z);
     }
}

class ResultDemo extends B
{ 
    ResultDemo(int x,int y)
    {
    super(x,y);
    }
    public static void main(String args[]) 
    { 
       A num1=new A(7,14);
       B num2=new B(7,14);
       ResultDemo num3=new ResultDemo(7,14);
       num1.display();
       num2.display();
       num3.display();
    }
}