1 #include <iostream>
 2
 3 /* run this program using the console pauser or add your own getch, system("pause") or input loop */
 4 using namespace std;
 5 //定义有两个虚函数的基类
 6 class Base {
 7 public:
 8     //定义两个虚函数
 9     virtual void aFn1(void){
10         cout<<"aFnl is in Base class."<<endl;
11     }
12     virtual void aFn2(void) {
13         cout<<"aFn2 is in Base class."<<endl;
14     }
15     //定义非虚函数
16     void aFn3(void) {
17         cout<<"aFn3 is in Base class."<<endl;
18     }
19 };
20
21 //派生类Derived_1中重新定义了基类中的虚函数aFn1
22 class Derived_1:public Base
23 {
24 public:
25     void aFn1(void) {   //覆盖aFn1()函数
26         cout<<"aFnl is in First derived class."<<endl;
27     }
28     // void aFn3(void) {   语法错误
29     //    cout<<"aFn3 is in First derived class."<<endl;
30     //}
31 };
32
33 //派生类Derived_2中重新定义了基类中的虚函数aFn2
34 class Derived_2:public Base{
35 public:
36     void aFn2(void){   //覆盖aFn2()函数
37         cout<<"aFn2 is in Second derived class."<<endl;
38     }
39     // void aFn3(void) {   语法错误
40     //    cout<<"aFn3 is in Second derived class."<<endl;
41     //}
42 };
43 //main()函数的定义
44
45 int main(int argc, char** argv) {
46
47     //创建和使用基类Base的对象
48     Base b;
49     cout<<"Base:"<<endl;
50     b.aFn1();
51     b.aFn2();
52     b.aFn3();
53     cout<<"----------------------"<<endl;
54
55     //创建和使用派生类Derived_1的对象
56     Derived_1 d1;
57     cout<<"Derived_1:"<<endl;
58     d1.aFn1();
59     d1.aFn2();
60     d1.aFn3();
61     cout<<"----------------------"<<endl;
62
63     //创建和使用派生类Derived_2的对象
64     Derived_2 d2;
65     cout<<"Derived_2:"<<endl;
66     d2.aFn1();
67     d2.aFn2();
68     d2.aFn3();
69     return 0;
70 }