C++上机实验报告实验六

1、实验六 多态性1. 实验目的1.掌握运算符重载的方法2.学习使用虚函数实现动态多态性2. 实验要求1.定义Point类，有坐标_x，_y两个成员变量；对Point类重载“”(自增)、“”(自减)运算符，实现对坐标值的改变。2.定义一个车(vehiele)基类，有Run、Stop等成员函数，由此派生出自行车(bicycle)类、汽车(motorcar)类，从bicycle和motorcar派生出摩托车(motorcycle)类，它们都有Run、Stop等成员函数。观察虚函数的作用。3. (选做)对实验4中的People类重载“”运算符和“=”运算符，“”运算符判断两个people类对象的id属性

2、是否相等；“=”运算符实现People类对象的赋值操作。3. 实验内容及实验步骤1.编写程序定义Point类，在类中定义整型的私有成员变量_x_y，定义成员函数Point& operator+()；Point operator+(int)；以实现对Point类重载“+”(自增)运算符，定义成员函数Point operator()；Point operator(int)；以实现对Point类重载“”(自减)运算符，实现对坐标值的改变。程序名：1ab8_1cpp。2.编写程序定义一个车(vehicle)基类，有Run、Stop等成员函数，由此派生出自行车(bicycle)类、汽车(moto

3、rcar)类，从bicycle和motorcar派生出摩托车(motorcycle)类，它们都有Run、Stop等成员函数。在main()函数中定义vehicle、bicycle、motorcar、motorcycle的对象，调用其Run()、Stop()函数，观察其执行情况。再分别用vehicle类型的指针来调用这几个对象的成员函数，看看能否成功；把Run、Stop定义为虚函数，再试试看。程序名：lab8_2cpp。4. 思考题1. 如何将一个运算符重载为类的成员函数？函数类型 operator 运算符（形参表） 函数体；2. 如何将一个运算符重载为类的友元函数？friend 函数类型 op

4、erator 运算符（形参表） 函数体；3.如何实现运行时刻的多态？在基类的成员函数前加上virtual，就可以在它的派生类中声明相同名字和类型的成员函数，在运行过程中，系统会自动判断并调用相应类中的成员函数，从而在调用过程中实现多态。5. 源程序1. lab8_1.cpp#include<iostream>using namespace std;class Pointprivate: int _x; int _y;public: /构造.析构函数 Point() Point(int,int); Point() /+.-重载 Point& operator +(); Poi

5、nt operator +(int); Point& operator -(); Point operator -(int); /输出点坐标 void showPoint();Point:Point(int x,int y) _x=x; _y=y;Point& Point:operator +() _x+; _y+; return *this;Point Point:operator +(int) Point p=*this; +(*this); return p;Point& Point:operator -() _x-; _y-; return *this;Poin

6、t Point:operator -(int) Point p=*this; -(*this); return p;void Point:showPoint() cout<<"The point is ("<<_x<<","<<_y<<")"<<endl;int main() Point apoint(3,5); apoint.showPoint(); (apoint+).showPoint();/测试后置+ apoint.showPoint(); (+apoin

7、t).showPoint();/测试前置+ apoint.showPoint(); (apoint-).showPoint();/测试后置- apoint.showPoint(); (-apoint).showPoint();/测试前置- apoint.showPoint(); return 0;2. lab8_2.cpp#include<iostream>using namespace std; class Vehiclepublic: /基类的成员函数为虚函数 virtual void run()cout<<"Vehicle is running!&quo

8、t;<<endl; virtual void stop()cout<<"Vehicle is stopping!"<<endl;class Bicycle: virtual public Vehicle/按虚基类继承public: void run()cout<<"Bicycle is running!"<<endl; void stop()cout<<"Bicycle is stopping!"<<endl;class Motorcar:virtua

9、l public Vehicle/按虚基类继承public: void run()cout<<"Motorcar is running!"<<endl; void stop()cout<<"Motorcar is stopping!"<<endl;class Motorcycle:public Bicycle,public Motorcarpublic: void run()cout<<"Motorcycle is running!"<<endl; void st

10、op()cout<<"Motorcycle is stopping!"<<endl;int main() Vehicle veh; Bicycle bic; Motorcar mot; Motorcycle m; /对象名.函数测试 /*veh.run(); veh.stop(); bic.run(); bic.stop(); mot.run(); mot.stop(); m.run(); m.stop();*/ /基类指针测试 Vehicle* p; p=&veh; p->run(); p->stop(); p=&bic

11、; p->run(); p->stop(); p=&mot; p->run(); p->stop(); p=&m; p->run(); p->stop(); return 0;3. lab8_3#include<iostream>#include<cstring>using namespace std;/Date类class Dateprivate:int year;int month;int day;public:Date();Date(int y,int m,int d);Date(Date &p);Dat

12、e();void setDate();void showDate();/People类，其中含Date类型的数据class Peopleprivate:char name11;char number7;char sex3;Date birthday;public:char id16;People();People(char* n,char* nu,char* s,Date b,char* i);People(People &p);People();bool operator =(People&);People& operator =(People&);void

13、setName();void setNumber();void setSex();void setId();void showPeople();/Date构造函数Date:Date()Date:Date(int y,int m,int d)year=y;month=m;day=d;Date:Date(Date &p)year=p.year;month=p.month;day=p.day;/析构inline Date:Date()/Date成员函数，设置出生年月日void Date:setDate()int y,m,d;cout<<"Input the year:&

14、quot;cin>>y;cout<<"Input the month:"cin>>m;cout<<"Input the day:"cin>>d;year=y;month=m;day=d;/Date内联成员函数，输出年月日inline void Date:showDate()cout<<"Birthday is "<<year<<"年"<<month<<"月"<<da

15、y<<"日"<<endl;/People构造函数People:People();People:People(char* n,char* nu,char* s,Date b,char* i)strcpy(name,n);strcpy(number,nu);strcpy(sex,s);birthday=b;strcpy(id,i);People:People(People &p)strcpy(name,);strcpy(number,p.number);birthday=p.birthday;strcpy(id,p.id);/Peop

16、le析构inline People:People()/People成员函数，设置各类数据void People:setName()cout<<"Please input the person's name:"cin.getline(name,11,'n');void People:setNumber()cout<<"Input number:"cin.getline(number,7,'n');void People:setSex()cout<<"Input sex:&

17、quot;cin.getline(sex,3,'n');void People:setId()cout<<"Input id:"cin.getline(id,16,'n');/People内联成员函数，输出人员信息inline void People:showPeople()cout<<"Name:"<<name<<endl;cout<<"Number:"<<number<<endl;cout<<"

18、Sex:"<<sex<<endl;cout<<"ID:"<<id<<endl;bool People:operator =(People& p)return id=p.id;People& People:operator =(People& p)strcpy(name,);strcpy(number,p.number);birthday=p.birthday;strcpy(id,p.id);return *this;/检测=重载的普通函数void test(People

19、& x,People& y)if(strcmp(x.id,y.id)=0)cout<<"Their's IDs are same"<<endl;elsecout<<"Their's IDs are different"<<endl;int main()/*int i;char spaceA;/生成3个Date类型的对象Date date3=Date(0,0,0),Date(0,0,0),Date(0,0,0);/生成3个People类型的对象People person3=Pe

20、ople("0","0","0",date0,"0"),People("0","0","0",date1,"0"),People("0","0","0",date2,"0");/设置这3个对象的各类信息for(i=0;i<3;i+)personi.setName();personi.setNumber();personi.setSex();personi.setId();datei.setDate();spaceA=getchar();/输出这3个对象的各类信息for(i=0;i<3;i+)personi.showPeople();datei.showDate();*/测试=重载Date d1(0,0,0);People p1("lizhibo"