1 public class ThisDemo{
 2     public static void main(String[] args){
 3         Dog d1 = new Dog(2,"小黄");
 4         Person p1 = new Person(d1,101,"周易");
 5         Person p2 = new Person(d1,10,"易周");
 6         p1.showInfo();
 7         p2.dog.showInfo();
 8     }
 9 }
10 //定义一个人类
11 class Person{
12     //成员变量
13     int age;
14     String name;
15     Dog dog;//引用类型
16     public Person(Dog dog,int age,String name){
17         /*可读性不好
18          age=age;
19          name=name;
20          */
21         //使用this区分局部变量与实例变量,提高可读性
22         this.age=age;
23         this.name=name;
24         this.dog = dog;
25     }
26     //显示人名字
27     public void showInfo(){
28         System.out.println("人名是："+name);
29     }
30 }
31 class Dog{
32     int age;
33     String name;
34     public Dog(int age,String name){
35         this.age = age;
36         this.name = name;
37     }
38     public void showInfo(){
39         System.out.println("狗名叫"+this.name);
40     }
41 }