实验5 继承和多态

任务3

源码：

 1 #pragma once
 2 
 3 #include <iostream>
 4 #include <string>
 5 
 6 using std::string;
 7 
 8 
 9 class MachinePets {
10 public:
11     MachinePets(const string &s);           
12 
13 public:
14     virtual string get_nickname() const = 0;                 
15     virtual string talk() const = 0;                
16 
17 protected:
18     string nickname;    
19 };
20 
21 MachinePets::MachinePets(const string &s): nickname{s} {
22 }
23 
24 
25 
26 class PetCats: public MachinePets {
27 public:
28     PetCats(const string &s);  
29 
30 public:
31     string get_nickname() const override;      
32     string talk() const override;         
33 
34 };
35 
36 PetCats::PetCats(const string &s): MachinePets{s} {
37 }
38 
39 string PetCats::get_nickname() const{
40     return nickname;
41 }
42 
43 string PetCats::talk() const {
44     return "miao wu~";
45 }
46 
47 
48 class PetDogs: public MachinePets {
49 public:
50     PetDogs(const string &s);  
51 
52 public:
53     string get_nickname() const override;      
54     string talk() const override;         
55 
56 };
57 
58 PetDogs::PetDogs(const string &s): MachinePets{s} {
59 }
60 
61 string PetDogs::get_nickname() const{
62     return nickname;
63 }
64 
65 string PetDogs::talk() const {
66     return "wang wang~";
67 }

 1 #include <iostream>
 2 #include <vector>
 3 #include "pets.hpp"
 4 
 5 void test() {
 6     using namespace std;
 7 
 8     vector<MachinePets *> pets;
 9 
10     pets.push_back(new PetCats("miku"));
11     pets.push_back(new PetDogs("da huang"));
12 
13     for(auto &ptr: pets)
14         cout <<ptr->get_nickname() << " says " << ptr->talk() << endl;
15 }
16 
17 int main() {
18     test();
19 }

运行测试截图：

任务4

 源码：