实验4 继承

实验三

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 class Car {
 5     public:
 6         Car(string z,string x,int y,int m=0):maker(z),model(x),year(y),odometers(m) {};
 7         void info(){
 8             cout<<"制造商：\t"<<maker<<endl;
 9             cout<<"型号：\t\t"<<model<<endl;
10             cout<<"生产年份：\t"<<year<<endl;
11             cout<<"当前行车里程数："<<odometers<<endl;
12         }
13         void update_odometers(int m){
14             if(m<odometers)
15                 cout<<"waring please enter again"<<endl;
16             odometers=m;
17         }
18     private:
19         string maker;
20         string model;
21         int year;
22         int odometers;
23 };
car.hpp
#include <iostream>
#include "electricCar.hpp"

int main()
{
    using namespace std;

    // test class of Car
    Car oldcar("Audi", "a4", 2016);
    cout << "--------oldcar's info--------" << endl;
    oldcar.update_odometers(25000);
    oldcar.info();

    cout << endl;

    // test class of ElectricCar
    ElectricCar newcar("Tesla", "model s", 2016);
    newcar.update_odometers(2500);
    cout << "\n--------newcar's info--------\n";
    newcar.info();
}
task3.cpp
 1 #include<iostream>
 2 
 3 class Battery {
 4     public:
 5         Battery(string a="70-kmh"):capacity(a) {};
 6         string get_capacity(){
 7             return capacity;
 8         };
 9     private:
10         string capacity;
11 };
battery.hpp
electriccar.hpp

 

 

实验四

 

 1 #ifndef PETS_HPP
 2 #define PETS_HPP
 3 #include <iostream>
 4 #include<string>
 5 using namespace std;
 6 class MachinePets{
 7     public:
 8         MachinePets(const string s):nickname(s){};
 9         string get_nickname()const{
10             return nickname;
11         }
12         virtual string talk(){
13         }
14     private:
15         string nickname;
16 };
17 
18 class PetCats:public MachinePets{
19     public:
20         PetCats(const string s):MachinePets(s){
21             
22         };
23         string talk(){
24             return "miao wu ~";
25         }
26 };
27 
28 class PetDogs:public MachinePets{
29     public:
30         PetDogs(const string s):MachinePets(s){};
31         string talk(){
32             return "wang wang wang !";
33         }
34 };
35 #endif
pets.hpp
 1 #include <iostream>
 2 #include "pets.hpp"
 3 #include<string>
 4 void play(MachinePets *ptr)
 5 {
 6     std::cout << ptr->get_nickname() << " says " << ptr->talk() << std::endl;
 7 }
 8 
 9 int main()
10 {
11     PetCats cat("miku");
12     PetDogs dog("da huang");
13 
14     play(&cat);
15     play(&dog);
16 }
task4.cpp

 

 

 

小结

1、在实验三中既用到了类的继承又用到了类的组合，组合中类对象的private成员也是不能在类中直接访问的，所以需要调用公有接口

2、virtual函数可以让派生类在和基类有同名函数时，基类的指针能指向传入的派生类中的函数

posted @ 2021-11-24 17:11  hyh&&tyq  阅读(21)  评论(3)  编辑  收藏  举报