java第十一天作业

作业如下图：

程序如下：

代码：

public class Homework6{
 public static void main(String[] args){
  Master m = new Master();
  Pet d = new Dog();
  Pet c = new Cat();
  Pet y = new YingWu();
  m.feed(d);
  m.feed(c);
  m.feed(y);
 } 
}
class Master{
 public void feed(Pet p){
  p.eat();
 }
}
class Pet{
 public void eat(){
  System.out.println("宠物在吃东西");
 }
}
class Dog extends Pet{
 public void eat(){
  System.out.println("狗在吃狗粮");
 }
}
class Cat extends Pet{
 public void eat(){
  System.out.println("猫在吃猫粮");
 }
}
class YingWu extends Pet{
 public void eat(){
  System.out.println("鹦鹉在吃鸟粮");
 }
}