实验四

实验四

1. 车辆基本信息管理问：基于Car类派生出ElectricCar类，派生类ElectricCar中新增数据成员为Battery类对象。

 1 #ifndef CAR_H
 2 #define CAR_H
 3 #include<iostream>
 4 using namespace std;
 5 
 6 class Car{
 7     public:
 8         Car(string maker0=" ",string model0=" ",int year0=2000);
 9         void updateOdometer(int newOdometer);
10         string Getmaker()const;
11         string Getmodel()const;
12         int Getyear()const;
13         int Getodometer()const;
14         friend ostream & operator<<(ostream &out,const Car &t);
15     private:
16         string maker;
17         string model;
18         int year;
19         int odometer;
20 };
21 
22 #endif
Car.h
 1 #include "car.h"
 2 #include<iostream>
 3 using namespace std;
 4 
 5 Car::Car(string maker0,string model0,int year0){
 6     maker=maker0;
 7     model=model0;
 8     year=year0;
 9     odometer=0;
10 }
11 
12 string Car::Getmaker()const{
13     return maker;
14 }
15 
16 string Car::Getmodel()const{
17     return model;
18 }
19 
20 int Car::Getyear()const{
21     return year;
22 }
23 
24 int Car::Getodometer()const{
25     return odometer;
26 }
27 
28 void Car::updateOdometer(int newOdometer){
29     if(odometer<odometer)
30     cout<<"Warning!Update data error."<<endl;
31     else
32     odometer=newOdometer;
33 }
34 
35 ostream & operator<<(ostream &out,const Car &t){
36     out<<"Maker:"<<t.maker<<endl<<"Model:"<<t.model<<endl<<"Year:"<<t.year<<endl<<"Odometer:"<<t.odometer<<endl;
37     return out;
38 }
Car.cpp
 1 #ifndef ELECTRIC_CAR_H
 2 #define ELECTRIC_CAR_H
 3 #include "battery.h"
 4 #include "car.h"
 5 
 6 class ElectricCar:public Car{
 7     public:
 8         ElectricCar(string maker0=" ",string model0=" ",int year0=2000,int odometer0=0);
 9         friend ostream & operator<<(ostream &out,const ElectricCar &m);
10     private:
11         Battery battery;
12         int batterysize;
13 };
14 
15 #endif
ElectricCar.h
 1 #include "electriccar.h"
 2 #include<iostream>
 3 #include "car.h"
 4 #include "battery.h"
 5 using namespace std;
 6 
 7 ElectricCar::ElectricCar(string maker0,string model0,int year0,int odometer):Car(maker0,model0,year0){
 8     batterysize=battery.GetbatterySize();
 9 }
10 
11 ostream & operator<<(ostream &out,const ElectricCar &m)
12 {
13     out<<"Maker:"<<m.Getmaker()<<endl
14        <<"Model:"<<m.Getmodel()<<endl
15        <<"Year:"<<m.Getyear()<<endl
16        <<"Odometer:"<<m.Getodometer()<<endl
17        <<"BatterSize:"<<m.batterysize<<"kWh"<<endl;
18     return out;
19 }
ElectricCar.cpp
 1 #ifndef BATTERY_H
 2 #define BATTERY_H
 3 
 4 class Battery{
 5     public:
 6         Battery(int batterySize0=70);
 7         int GetbatterySize();
 8     private:
 9         int batterySize;
10 };
11 
12 #endif
Battery.h
 1 #include "battery.h"
 2 #include<iostream>
 3 using namespace std;
 4 
 5 Battery::Battery(int batterySize0){
 6     batterySize=batterySize0;
 7 }
 8 
 9 int Battery::GetbatterySize(){
10     return batterySize;
11 }
Battery.cpp
 1 #include <iostream>
 2 #include<cstdlib>
 3 using namespace std;
 4 
 5 #include "car.h"
 6 #include "electricCar.h" 
 7 
 8 int main() {
 9     // 测试Car类 
10     Car oldcar("Audi","a4",2016);
11     cout << "--------oldcar's info--------" << endl;
12     oldcar.updateOdometer(25000);
13     cout << oldcar << endl;
14 
15     // 测试ElectricCar类 
16     ElectricCar newcar("Tesla","model s",2016);
17     newcar.updateOdometer(2500);
18     cout << "\n--------newcar's info--------\n"; 
19     cout << newcar << endl;
20 
21     system("pause");
22     
23     return 0;
24 }
main.h

实验结果如下：

 

2.2. 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。

 1 #ifndef ARRAY_INT_H
 2 #define ARRAY_INT_H
 3 
 4 class ArrayInt{
 5     public:
 6         ArrayInt(int n, int value=0);
 7         ~ArrayInt();
 8         // 将运算符[]重载为成员函数的声明
 9         int& operator[](int x); 
10         void print(); 
11     private:
12         int *p;
13         int size;
14 };
15 
16 #endif
ArrayInt.h
 1 #include "arrayInt.h"
 2 #include <iostream>
 3 #include <cstdlib>
 4 using std::cout;
 5 using std::endl;
 6 
 7 ArrayInt::ArrayInt(int n, int value): size(n) {
 8     p = new int[size];
 9     
10     if (p == 0) {
11         cout << "fail to mallocate memory" << endl;
12         exit(0); 
13     } 
14     
15     for(int i=0; i<size; i++)
16         p[i] = value;
17 }
18 
19 ArrayInt::~ArrayInt() {
20     delete[] p;
21 }
22 
23 void ArrayInt::print() {
24     for(int i=0; i<size; i++)
25         cout << p[i] << " ";
26     cout << endl;
27 }
28 
29 // 运算符[]重载为成员函数的实现
30 int &ArrayInt::operator[](int x){
31     return p[x];
32 }
ArrayInt.cpp
 1 #include <iostream>
 2 using namespace std;
 3 
 4 #include "arrayInt.h"
 5 
 6 int main() {
 7     // 定义动态整型数组对象a，包含2个元素，初始值为0
 8     ArrayInt a(2);
 9     a.print();
10     
11     // 定义动态整型数组对象b，包含3个元素，初始值为6
12     ArrayInt b(3, 6);
13     b.print();
14 
15     // 通过对象名和下标方式访问并修改对象元素
16     b[0] = 2;
17     cout << b[0] << endl;
18     b.print();
19 
20     system("pause");
21 
22     return 0;
23 }
main.h

运行结果如下：

说一说实验中遇到的三个令我头大的点，一是程序头文件的包含与被包含，这个可以自己慢慢熟悉记忆，二是在vs2010环境下，对于派生出来的类中添加的重载运算符部分的定义不明确，在devc环境中自身优化后就没有这样的问题，这个仍然不明确原因，三是构造函数的初始化列表，看了几个博文，其中作小推荐：http://www.cnblogs.com/kaituorensheng/p/3477630.html，以及这位博客：https://www.cnblogs.com/kaituorensheng/category/465181.html

 

 

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posted @ 2019-05-14 22:13  DADABud  阅读(119)  评论(1)  编辑  收藏  举报