实验4

1：

#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;
}

#ifndef ARRAY_INT_H
#define ARRAY_INT_H

class ArrayInt{
    public:
        ArrayInt(int n, int value=0);
        ~ArrayInt();
        int & operator[](int a);
        void print(); 
    private:
        int *p;
        int size;
};

#endif

#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) {
        cout << "fail to mallocate memory" << endl;
        exit(0); 
    } 
    
    for(int i=0; i<size; i++)
        p[i] = value;
}

ArrayInt::~ArrayInt() {
}

void ArrayInt::print() {
    for(int i=0; i<size; i++)
        cout << p[i] << " ";
    cout << endl;
}

int & ArrayInt::operator[](int a){
    return p[a];
}
// 补足:将运算符[]重载为成员函数的实现
// ×××

2:

#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;
}

#ifndef CAR_H
#define CAR_H
#include<iostream>
#include<string>
using namespace std;

class Car{
    public:
        Car(string maker0,string model0,int year0,int odometer0=0):maker(maker0),model(model0),year(year0),odometer(odometer0){}
        friend ostream& operator<<(ostream &out, const Car &c);
        void updateOdometer(int odometer1);
        string maker,model;
        int year,odometer;
};
#endif

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

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 odometer1){
    if(odometer1<odometer) 
    cout<<"warning:wrong number"<<endl;
    else 
    odometer=odometer1;
}

#ifndef BATTERY_H
#define BATTERY_H

class Battery{
    public:
        Battery(int batterySize0=70);
        int batterySize;
        int returnsize();
};
#endif 

#include"battery.h"

Battery::Battery(int batterySize0){
    batterySize=batterySize0;
}

int Battery::returnsize(){
    return batterySize;
}

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

class ElectricCar:public Car,public Battery{
    public:
        ElectricCar(string maker1,string model1,int year1,int odometer1=0,int batterySize1=70):Car(maker1,model1,year1,odometer1),Battery(batterySize1){}
        friend ostream& operator<<(ostream &outCar, const ElectricCar &e);
        void updateOdometer(int odometer1);
};
#endif

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

ostream& operator<<(ostream &out, const ElectricCar &e) {
    out << "maker:" << e.maker << endl << "model:" << e.model << endl << "year:" << e.year << endl << "odometer:" << e.odometer << endl << "batterySize:" << e.batterySize << endl;
    return out;
}

void ElectricCar::updateOdometer(int odometer1) {
    if(odometer1<odometer) 
    cout<<"warning:wrong number"<<endl;
    else 
    odometer=odometer1;
}

 

第二题dev做了好久，实在没有办法去下了个vs2017再调了一会终于做出来了，第一题中因为是dev所以，P=nullptr那里用的是!p。还有好多小细节的问题。以前落了好多进度啊。