实验4 类的继承、派生和多态(1)

1. 车辆基本信息管理

#include <iostream>
using namespace std;

#include "car.h"
#include "electricCar.h" 

int main() {
    // 测试Car类 
    car oldcar("Audi", "a4", 2016);
    cout << "--------oldcar's info--------" << endl;
    oldcar.update(25000);
    cout << oldcar << endl;

    // 测试ElectricCar类 
    electricCar newcar("Tesla", "model s", 2016);
    newcar.update(2500);
    cout << "\n--------newcar's info--------\n";
    cout << newcar << endl;

    system("pause");

    return 0;
}

#ifndef CAR_H
#define CAR_H
#include<iostream>
#include<string>
using namespace std;
class car{
public:
    car(string ma, string mo, int ye, int odo = 0) :maker(ma), model(mo), year(ye), odometer(odo) {}
    friend ostream & operator<<(ostream &out,const car &c);
    void update(int odo1);
    string maker,model;
    int year,odometer;
};

#endif

#include"car.h"
#include<iostream>
#include<string>
using std::cout;
using std::endl;

ostream & operator<<(ostream &out, const car &c) {
    out << "maker:" << c.maker << endl << "moder:" << c.model << endl << "year:" << c.year << endl << "odometer:" << c.odometer << endl;
    return out;
}

void car::update(int odo1) {
    if (odo1 < odometer) cout << "the number is wrong" << endl;
    else odometer = odo1;
}

#ifndef BATTERY_H
#define BATTERY_H

class battery{
public:
    battery(int size = 70);
    int fh();
    int batterySize;
};
#endif

 

#include"battery.h"
#include<iostream>
using std::cout;
using std::endl;

battery::battery(int size) {
    batterySize = size;
}
int battery::fh() {
    return batterySize;
}

#ifndef ELECTRICCAR_H
#define ELECTRICCAR_H
#include"car.h"
#include"battery.h"
#include<iostream>
#include<string>

class electricCar :public car, public battery {

public:
    electricCar(string ma2, string mo2, int ye2, int odo2 = 0, int size1 = 70) :car(ma2, mo2, ye2, odo2), battery(size1) {}
    friend ostream& operator<<(ostream &outCar, const electricCar &a);
    void updateOdometer(int odo1);
};
#endif

#include"electricCar.h"
#include"battery.h"
#include"car.h"
#include<iostream>
using namespace std;

ostream& operator<<(ostream &out, const electricCar &a) {
    out << "maker:" << a.maker << endl << "moder:" << a.model << endl << "year:" << a.year << endl << "odometer:" << a.odometer << endl << "batterySize:" << a.batterySize << "-kWh" << endl;
    return out;
}
void electricCar::updateOdometer(int odo1) {
    if (odo1 < odometer) cout << "the number is wrong" << endl;
    else odometer = odo1;
}

 

 

 

2. 补足程序，重载运算符[]为一维动态整形数组类ArrayInt的成员函数，使得通过动态整形数组对象名和下标可以 访问对象中具体元素。

#include <iostream> 
using namespace std;
#include "arrayInt.h"
int main() {    
    // 定义动态整型数组对象a，包含2个元素，初始值为0    
    ArrayInt a(2);    
    a.print();     
    // 定义动态整型数组对象b，包含3个元素，初始值为6    
    ArrayInt b(3, 6);   
    b.print();
    // 通过对象名和下标方式访问并修改对象元素    
    b[0] = 2;    
    cout << b[0] << endl;    
    b.print();
    system("pause");
    return 0;
}

#include "arrayInt.h"
#include <iostream>
#include <cstdlib>
using std::cout;
using std::endl;
ArrayInt::ArrayInt(int n, int value) : size(n) {
    p = new int[size];
    if (p == nullptr) {
        cout << "fail to mallocate memory" << endl;
        exit(0);
    }
    for (int i = 0; i < size; i++)
        p[i] = value;
}
ArrayInt::~ArrayInt() {
    delete[] p;
}
void ArrayInt::print() {
    for (int i = 0; i < size; i++)
        cout << p[i] << " ";
    cout << endl;
}
// 补足:将运算符[]重载为成员函数的实现
// ×××
int &ArrayInt::operator[](int m) {
    return p[m];
}

#ifndef ARRAY_INT_H
#define ARRAY_INT_H
class ArrayInt {
public:
    ArrayInt(int n, int value = 0);
    ~ArrayInt();
    // 补足:将运算符[]重载为成员函数的声明
    // ×××
    int & operator[](int m);
    void print();
private:
    int *p;
    int size;
};
#endif

 

 

结论：

重载函数不能继承private里的变量，所以都放在public里定义了。

car函数定义变量比较多，前后一定要一致，我把main里的"electricCar"  改成了 "ElectricCar"，“car”改成了“Car”所以总是运行不出结果。