Java 4 day 

 1 package Joker;
 2 /*Object
 3  * 所有没集成关系类的，默认父类
 4  * 通过向上造型，所有类都可以造型成Object
 5  * java.lang.Object
 6  * 
 7  * toString
 8  * 不重写：类名@散列码
 9  * 重写：放在return语句后
10  * equals
11  * 不重写：==
12  * 重写：想比啥比啥
13  * 
14  * 
15  */
16 public class Animal {
17     String name;
18     int age;
19     String p;
20     public Animal() {
21         
22     }
23     public Animal(String name,int age,String p) {
24         this.name=name;
25         this.age=age;
26         this.p=p;
27     }
28     @Override
29     public String toString() {
30         
31         return "name:"+name+"  age:"+age+"  p:"+p;
32     }
33     @Override
34     public boolean equals(Object a) {
35         if(a==null){
36             return false;
37         }
38         if(a==this){
39             return true;
40         }
41         if(a instanceof Animal){
42             Animal b=(Animal)a;
43             return b.name==name&&b.age==age;
44         }else{
45             return false;
46     }
47     }    
48     
49 
50 }
 1 package Joker;
 2 
 3 public class Test {
 4 
 5     public static void main(String[] args) {
 6         Animal a=new Animal("哇咔咔",1,"biubiubiu");
 7         System.out.println(a);
 8         Cat b=new Cat();
 9         a.equals(b);
10 
11     }
12 
13 }
1 package Joker;
2 
3 public class Cat extends Animal{
4 
5 }

 

posted @ 2021-04-17 17:04  WakkJoker  阅读(51)  评论(0)    收藏  举报