4.21 

 1 #include<iostream>
 2 using namespace std;
 3 class BaseClass
 4 {
 5 public:
 6     BaseClass()
 7     {
 8         cout<<"构造基类对象"<<endl; 
 9     }
10 };
11 class DerivedClass:public BaseClass
12 {
13 public:
14     DerivedClass()
15     {
16         cout<<"构造派生类对象"<<endl;
17     }
18 };
19 int main()
20 {
21     DerivedClass d;
22 }
 1 #include<iostream>
 2 using namespace std;
 3 class BaseClass
 4 {
 5 public:
 6     int fn1()
 7     {
 8         cout<<"调用基类的函数fn1()"<<endl; 
 9     }
10     int fn2() 
11     {
12         cout<<"调用基类的函数fn2()"<<endl;
13     }
14 };
15 class DerivedClass:public BaseClass
16 {
17 public:
18     int fn1() 
19     {
20         cout<<"调用派生类的函数fn()1"<<endl;
21     }
22     int fn2() 
23     {
24         cout<<"调用派生类的函数fn()2"<<endl;
25     }
26 };
27 int main()
28 {
29     DerivedClass a;
30     DerivedClass *p1=&a;
31     BaseClass *p2=&a;
32     a.fn1();
33     a.fn2();
34     p1->fn1();
35     p1->fn2();
36     p2->fn1();
37     p2->fn2();
38 }

 

posted @ 2023-04-21 22:23  Code13  阅读(93)  评论(0)    收藏  举报