1 class Animala{
2 void makeNoise(){
3 System.out.println("动物在嘶吼");
4 }
5 }
6 class Dogs extends Animala{
7 void makeNoise(){ //重写
8 System.out.println("狗的叫声是汪汪汪");
9 }
10 }
11 class Cat extends Animala{
12 void makeNoise(){
13 System.out.println("猫的叫声是喵呜呜呜呜");
14 }
15 }
16 class Vet{
17 public void giveShot(Animala a){
18 a.makeNoise();
19 }
20 }
21 public class Canshufanhui {
22 void start(){
23 Vet v = new Vet();
24 Dogs d = new Dogs();
25 Cat c = new Cat();
26 v.giveShot(d); //giveshot接受的是animala类型的参数，Dogs继承自animala，利用了参数多态
27 v.giveShot(c);
28 }
29 public static void main(String[] args){
30 Canshufanhui p = new Canshufanhui();
31 p.start();
32 }
33
34 }
