面向对象->实验报告四(C++)

task3

题目要求

源码

main.cpp

#include <iostream>#include "electricCar.hpp"int main(){using namespace std;// test class of CarCar oldcar("Audi", "a4", 2016);cout << "--------oldcar\'s info--------" << endl;oldcar.update_odometers(25000);oldcar.info();cout << endl;// test class of ElectricCarElectricCar newcar("Tesla", "model s", 2016);newcar.update_odometers(2500);cout << "\\n--------newcar\'s info--------\\n";newcar.info();ElectricCar anothercar("Tesla", "model Y", 2018, 180);anothercar.update_odometers(5200);cout << "\\n--------anothercar\'s info--------\\n";anothercar.update_odometers(230);anothercar.info();}

battery.hpp

#ifndef CPP_BATTERY_HPP#define CPP_BATTERY_HPPclass Battery{public:Battery(double _cap = 70):capacity(_cap){};double get_capacity(){return capacity;};private:double capacity;};#endif //CPP_BATTERY_HPP

car.hpp

#ifndef CPP_CAR_HPP#define CPP_CAR_HPP#include "iostream"#include "string"#include "iomanip"using namespace std;class Car{public:Car(string _maker, string _model, int _year, int _odometers = 0):maker(_maker), model(_model), year(_year), odometers(_odometers){}virtual void info();void update_odometers(int);protected:string maker, model;int year, odometers;};void Car::info() {cout << left << setw(16) << "maker:\\t" << maker << endl;cout << left << setw(16) << "model:\\t" << model << endl;cout << left << setw(15) << "year:\\t" << year << endl;cout << left << setw(12) << "odometers:\\t" << odometers << endl;}void Car::update_odometers(int _tempOdometers) {if(_tempOdometers < odometers)cout << "Change failed." << endl;elseodometers = _tempOdometers;}#endif //CPP_CAR_HPP

electricCar.hpp

#ifndef CPP_ELECTRICCAR_HPP#define CPP_ELECTRICCAR_HPP#include "car.hpp"#include "battery.hpp"class ElectricCar:public Car{private:Battery battery;public:ElectricCar(string, string, int, int);virtual void info();};ElectricCar::ElectricCar(string _maker, string _model, int _year, int capacity = 70):Car(_maker, _model, _year), battery(capacity){}void ElectricCar::info() {cout << left << setw(16) << "maker:\\t" << maker << endl;cout << left << setw(16) << "model:\\t" << model << endl;cout << left << setw(15) << "year:\\t" << year << endl;cout << left << setw(12) << "odometers:\\t" << odometers << endl;cout << left << setw(10) << "capacity\\t" << battery.get_capacity() << endl;}#endif //CPP_ELECTRICCAR_HPP

运行截图

总结

• 在所给主函数的基础上增加了对于

  electricCar

  构造函数初始化

  capacity

  和修改

  capacity

  的测试

• IDE的不同和不同操作系统间的等宽字体、编码问题，可能输出的对齐方式会有问题。当前测试环境:

  MacOS 11.6 VSCode

• 在使用派生类对基类进行初始化的时候需要注意其逻辑方式

task4

题目要求

源码

main.cpp

#include <iostream>#include "pets.hpp"void play(MachinePets *ptr){std::cout << ptr->get_nickname() << " says " << ptr->talk() <<std::endl;}int main(){PetCats cat("miku");PetDogs dog("da huang");play(&cat);play(&dog);}

pets.hpp

#ifndef MAIN_CPP_PETS_HPP#define MAIN_CPP_PETS_HPP#include "iostream"#include "string"using namespace std;class MachinePets{private:string nickname;public:MachinePets(const string s);string get_nickname() const{return nickname;};virtual string talk();};class PetCats:public MachinePets{public:PetCats(const string s);string talk();};class PetDogs:public MachinePets{public:PetDogs(const string s);string talk();};MachinePets::MachinePets(const string s):nickname(s) {}string MachinePets::talk() {string say = "hello";return say;}PetCats::PetCats(const string s):MachinePets(s){}string PetCats::talk() {return "miao wu~";}PetDogs::PetDogs(const string s):MachinePets(s){}string PetDogs::talk() {return "wang wang~";}#endif //MAIN_CPP_PETS_HPP

运行截图

总结

• 练习了基本的继承逻辑、原理、应用实践，对于基类与派生类构造函数的实现有了一定的理解