C++（实验四）

Part 1. Car

车辆基本信息管理 问题场景描述如下： 为了对车量基本信息进行管理，对现实世界车量基本信息抽象后，抽象出Car类、ElectricCar类、Battery类， 它们之间的关系描述如下：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。

程序源码：

 1 #ifndef CAR_H
 2 #define CAR_H
 3 #include <iostream>
 4 #include <string>
 5 using namespace std;
 6 
 7 class Car{
 8 public:
 9     Car(string maker0,string model0,int year0,int odometer0=0);
10     friend ostream & operator<< (ostream &out,const Car &c);
11     int updateOdometer(int newodometer);
12     string getmaker(){return maker;}
13     string getmodel(){return model;}
14     int getyear(){return year;}
15     int getodometer(){return odometer;}
16 private:
17     string maker;
18     string model;
19     int  year;
20     int  odometer;
21 };
22 
23 #endif

car.h

 1 #include "car.h"
 2 #include <iostream>
 3 #include <string>
 4 using namespace std;
 5 
 6 Car::Car(string maker0,string model0,int year0,int odometer0):maker(maker0),model(model0),year(year0),odometer(odometer0){
 7 }
 8 
 9 ostream & operator<< (ostream &out,const Car &c){
10     out<<" maker:"<<c.maker<<endl;
11     out<<"model:"<<c.model<<endl;
12     out<<"year:"<<c.year<<endl;
13     out<<"odometer:"<<c.odometer<<endl;
14     return out;
15 }
16 
17 int Car::updateOdometer(int newodometer){
18     if(newodometer<odometer)
19         cout<<"error!"<<endl;
20     else
21         odometer=newodometer;
22     return odometer;
23 }

car.cpp

 1 #ifndef BATTERY_H
 2 #define BATTERY_H
 3 
 4 class Battery{
 5 public:
 6     Battery(int batterySize0=70);
 7     int getbatterySize();
 8     friend class ElectricCar;
 9 private:
10     int batterySize;
11 };
12 
13 #endif

battery.h

1 #include "battery.h"
2 
3 Battery::Battery(int batterySize0):batterySize(batterySize0){
4 }
5 
6 int Battery::getbatterySize(){
7     return batterySize;
8 }

battery.cpp

 1 #ifndef ELECTRICAR_H
 2 #define ELECTRICAR_H
 3 #include "battery.h"
 4 #include "car.h"
 5 #include <string>
 6 #include <iostream>
 7 using namespace std;
 8 class Battery;
 9 
10 
11 class ElectricCar:public Car{
12 public:
13     ElectricCar(string maker0,string model0,int year0,int odometer0=0,int battery0=70);
14     friend ostream & operator<< (ostream &out,ElectricCar &c1);
15     friend class Battery;
16 private:
17     Battery b;
18     int batterysize;
19 };
20 
21 #endif

electricCar.h

 1 #include "electricCar.h"
 2 using namespace std;
 3 
 4 ElectricCar::ElectricCar(string maker0,string model0,int year0,int odometer0,int battery0):Car(maker0,model0,year0,odometer0){
 5     b.batterySize=battery0;
 6     batterysize=b.getbatterySize();
 7 }
 8 
 9 ostream & operator<< (ostream &out,ElectricCar &c1){
10     out<<"maker:"<<c1.getmaker()<<endl;
11     out<<"model:"<<c1.getmodel()<<endl;
12     out<<"year:"<<c1.getyear()<<endl;
13     out<<"odometer:"<<c1.getodometer()<<endl;
14     out<<"batterySize:"<<c1.batterysize<<"-kWh"<<endl;
15     return out;
16 }

electricCar.cpp

 1 #include <iostream>
 2 using namespace std;
 3 
 4 #include "car.h"
 5 #include "electricCar.h" 
 6 
 7 int main() {
 8     Car oldcar("Audi","a4",2016);
 9     cout << "--------oldcar's info--------" << endl;
10     oldcar.updateOdometer(25000);
11     cout << oldcar << endl;
12 
13     ElectricCar newcar("Tesla","model s",2016);
14     newcar.updateOdometer(2500);
15     cout << "\n--------newcar's info--------\n"; 
16     cout << newcar << endl;
17 
18     system("pause");
19     
20     return 0;
21 }

main.cpp

运行截图:

Part 2. Arraylnt

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。 

程序源码：

 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     int& operator[](int position);
 9     void print();
10 private:
11     int *p;
12     int size;
13 };
14 
15 #endif

arraylnt.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 == nullptr) {
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 int& ArrayInt::operator[](int position){
30     return p[position];
31 }

arraylnt.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.cpp

运行截图:

评论链接：
https://www.cnblogs.com/DADABu-21/p/10732017.html#4260437

https://www.cnblogs.com/lszz/p/10727553.html#4260428

https://www.cnblogs.com/Yyaoyyy/p/10751510.html#4260404