阿里巴巴2015实习生在线笔试题

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 class animal
 6 {
 7 public:
 8     virtual void print_age(void)=0;
 9 protected:
10     int age;
11 };
12 class dog: public animal
13 {
14 public:
15     dog(){this->age = 2;}
16     ~dog(){}
17     virtual void print_age(void){cout<<"wang:my age="<<this->age<<endl;}
18 };
19 
20 class cat: public animal
21 {
22 public:
23     cat(){this->age = 1;}
24     ~cat(){}
25     virtual void print_age(void){cout<<"miao:my age="<<this->age<<endl;}
26 };
27 int main()
28 {
29     cat kitty;
30     dog jd;
31     animal *pa;
32 
33     int *p = (int *)(&kitty);
34     int *q = (int *)(&jd);
35     p[0] = q[0];
36     pa = &kitty;
37     pa->print_age();
38     system("pause");
39     return 0;
40 }