实验

#ifndef BATTERY_H
#define BATTERY_H
class Battery{
    public:
        Battery(int b=70);
        int bb();
    private:
        int batterySize;
};
#endif

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

 Battery::Battery(int b):batterySize(b){
 }
 int Battery::bb(){
     return batterySize;
 }

#ifndef CAR_H
#define CAR_H
#include <iostream>
#include <string>
using std::string;
class Car{
    public:
        Car(string ma,string mo,int ye,int od=0);
        friend std::ostream & operator << (std::ostream &out,Car &c);
        int updateOdometer(int a);
        string mak();
        string mod();
        int yea();
        int odo();
    private:
        string maker;
        string model;
        int year;
        int odometer;
};
#endif

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

Car::Car(string ma,string mo,int ye,int od):maker(ma),model(mo),year(ye),odometer(od) {
}
string Car::mak(){
    return maker;
} 
string Car::mod(){
    return model;
}
int Car::yea(){
    return year;
}
int Car::odo(){
    return odometer;
}
std::ostream & operator <<(std::ostream &out,Car &c){
    out<<"maker: "<<c.maker<<endl
    <<"model: "<<c.model<<endl
    <<"year: "<<c.year<<endl
    <<"odometer: "<<c.odometer<<endl;
    return out;
}
int Car::updateOdometer(int a){
    if(odometer<=a)
    cout<<"error!"<<endl;
    else{
        odometer=a;
        cin>>odometer;
    }
    return odometer;
}

#ifndef ELECTRICCAR_H
#define ELECTRICCAR_H
#include "car.h"
#include "battery.h"
#include <string>
using std::string;
class ElectricCar:public Car,public Battery{
    public:
        ElectricCar(string ma,string mo,int ye,int od=0);
        friend std::ostream & operator <<(std::ostream &out,Car &c);
};
#endif 

#include "car.h"
#include "battery.h"
#include "electricCar.h"
#include <iostream>
using namespace std;
ElectricCar::ElectricCar(string ma,string mo,int ye,int od):Car(ma,mo,ye,od){
}
std::ostream & operator<<(std::ostream &out,ElectricCar &c){
    out<<"maker: "<<c.mak()<<endl
    <<"model: "<<c.mod()<<endl
    <<"year: "<<c.yea()<<endl
    <<"odomter: "<<c.odo()<<endl
    <<"batterySize: "<<c.bb()<<"-KWh"<<endl;
    return out;
}

#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 == NULL) {
        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;
}
int &ArrayInt:: operator [](int v){
    return p[v];
}

#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 <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;
}

实验总结：参照了之前做的实验和书本，能够更加熟练的运用构造函数，同时也复习了不太熟悉的友元和重载函数