is A和has A的区别

is A和has A的区别

2025-01-31 08:19:28 来源: 阅读:

is A

has A

Red is A Color:

class Red extends Color{}

class Blue extends Color{}

class Yellow exrends Color{}

She has A friend：

class She{

private Person friend;

}

继承关系

（分为：

接口继承——扩展父类类型或功能

略

实现继承——实现公共代码的重用

 1  class Red extends Color{
 2 
 3              public void sayHello(){
 4 
 5                   System.out.print("大家好,");
 6 
 7                             }
 8 
 9                      }
10 
11 class Red extends Color{
12 
13                 @OverWrite
14 
15                 public void sayHello(){
16 
17                    super.sayHello();
18 
19                    System.out.println("我叫red!");
20 
21                      }
22 
23                  }
24 
25 
26  class Blue extends Color{
27 
29                  @OverWrite
31 
32                  public void sayHello(){
34 
35                        super.sayHello(); 
37 
38                        System.out.println("我叫blue!"); 
40 
41                        }
42 
43 
44                   }

从属关系

爱程序网

Tags：[db:关键字]