第四次实验

一car

main.cpp

#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.updateOdometer(25000);
    cout << oldcar << endl;

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

    system("pause");
    
    return 0;
}

battery.h

#ifndef BATTERY_H
#define BATTERY_H
class battery{
public:
    battery(int bs=70);
    int ret()const;
private:
    int batterySize;
};

#endif

battery.cpp

#include<iostream>
#include"battery.h"
using namespace std;
battery::battery(int bs):batterySize(bs){
}
int battery::ret()const{
    return batterySize;
}

car.h

#ifndef CAR_H
#define CAR_H
#include<string>
#include<iostream>
using namespace std;
class car{
public:
    car(string mer,string mel,int yar);
    friend ostream &operator<<(ostream &out,const car &c);
    void updateOdometer(int a);
private:
    string maker;
    string model;
    int year;
    int odometer;
};
#endif

car.cpp

#include<iostream>
#include<cstring>
#include"car.h"
car::car(string mer,string mel,int yar):maker(mer),model(mel),year(yar),odometer(0){
}
ostream &operator<<(ostream &out,const car &c){
    out<<"maker:"<<c.maker<<endl
       <<"model:"<<c.model<<endl
       <<"year:"<<c.year<<endl
       <<"odometer:"<<c.odometer<<endl;
    return out;
}
void car::updateOdometer(int a){
    if(a>=odometer)
    odometer=a;
    else
    cout<<"警告，更新数据有误"<<endl;
}

electriccar.h

#ifndef ELECTRICCAR_H
#define ELECTRICCAR_H
#include"car.h"
#include"battery.h"
#include<iostream>
#include<string>
class ElectricCar:public car{
public:
    ElectricCar(string mer,string mel,int yar,int bs=70);
    friend ostream &operator<<(ostream &out,const ElectricCar &c);
private:
    battery a;
};
#endif

electriccar.cpp

#include<iostream>
#include<string>
#include"electricCar.h"
ElectricCar::ElectricCar(string mer,string mel,int yar,int bs):car(mer,mel,yar),a(bs){
}
ostream &operator<<(ostream &out,const ElectricCar &c){
    car b=c;
    out<<b;
    out<<c.a.ret()<<endl;
    return out;
}

在main改变了几个字母

二arraylnt

arraylnt.h

#ifndef ARRAY_INT_H
#define ARRAY_INT_H

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

#endif

arraylnt.cpp

#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];
    
    
    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 i){
    return p[i];
}

main.cpp

#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;
}