e3_7.java

java 初学者学习实例

import java.applet.*;
import java.awt.*;
class Chengji
{
   float f(float x,float y)
   { 
        return x*y;
   }
}
class Xiangjia extends Chengji
{
   float f(float x,float y)
   {
       return x+y;
   }
}
public class E3_7 extends Applet 
{
   Xiangjia sum;//sum.f(4,5)=?
}