Question

我试图在Passenger和Bus类之间进行聚合，[wheel，door，engine]和Bus class之间的组合，[car，bus]和Vehicle的简单关联。此外，Driver与Car相关联。但我不知道如何用C ++代码编写它。我的程序在语法上是正确的，但给出了运行时错误。请帮我。

    #include<iostream>
#include<string>
using namespace std;

class Vehicle
{};

class Bus
{
    Door door;
    Wheel wheel;
    Engine engine;
    Passenger P;

    string busNo;

    int SeatingCapacity, SeatsReservedSofar;

public:
    int GetSeatingCapacity();
    void SetSeatingCapacity(int bCap);
    string GetBusNo();
    void SetBusNo(string bNo);
    void ReserveSeat(Passenger P); 
    void DisplayInfo();
};

class Passenger
{
    string Name;
    char Gender;

public:
    void SetPassengerName(string name);
    string GetPassengerName();
    void SetGender(char gender);
    char GetGender();
};

class Car
{};

class Driver
{

};

class Wheel
{

};

class Door
{

};

class Engine
{

};


////////////////////////////////////
//Definition of Functions
////////////////////////////////////
Bus::Bus()
{
cout<<"Creating a new bus..."<<endl;
}

void Bus::SetSeatingCapacity(int bCap)
{
    if(bCap>20 && bCap<50)
        SeatingCapacity=bCap;
}

void Bus::SetBusNo(string bNo)
{
    int len=bNo.length();
    if(len>2 && len<5)
        busNo=bNo;
}

void Passenger::SetPassengerName(string pname)
{
    int len=pname.length;
    if(len>0 && len<40)
        Name=pname;
}

void Passenger::SetGender(char pgender)
{
    if(pgender=='m' || pgender=='f')
        Gender=pgender;
}

void Bus::ReserveSeat(Passenger P)
{

    int capacity = GetSeatingCapacity(), rem;

    if(capacity != SeatsReservedSofar)
    {
        SeatsReservedSofar++;
        cout<<endl<<"Seat reserved for passenger";
        rem=capacity-SeatsReservedSofar;
        cout<<endl<<"Remaining Capacity : "<<rem;
    }
    else
    {
        cout<<endl<<"Seat reservation failed. No space left. ";
    }
}


int main()
{
Bus abus;

cout<<"Enter max capacity of bus for passengers : ";

int capacity;
cin>>capacity;
abus.SetSeatingCapacity(capacity);

cout<<endl<<"Enter the bus registration no : ";
string regno;
std::getline(std::cin,regno);
cin.ignore();
abus.SetBusNo(regno);

cout<<endl<<".....Bus is created successfully. "<<endl<<endl;

string pname;
Passenger passenger;
char gender;

cout<<"Enter the passenger name: ";
std::getline(std::cin, pname);
cin.ignore();
passenger.SetPassengerName(pname);
cout<<"Enter the passenger gender <m for male and f for female>";
cin>>gender;
passenger.SetGender(gender);
abus.ReserveSeat(passenger);

char quest;
for(quest='y'; quest == 'y'; )
{
cout<<endl<<endl<<"Do you want to add more passengers? (y/Y for yes and another character for no)? ";
char quest;
cin>>quest;
}

system("pause");

}

Answer 1

首先我认为你的程序无法编译，为什么？

你在公共汽车课上放置了Passanger，Door，Wheel和Engine。在Bus类编译时，编译器不知道这些类型 - 您需要在Bus之前定义它们以在Bus定义中使用它们，
在类定义中没有声明Bus构造函数，它放在类外面，它不会那样工作，你需要在Bus类中添加Bus（），
在Passenger :: SetPassengerName中，你忘了长篇大括号，
您忘了定义GetSeatingCapacity（）方法，

如果有预订系统，您可以考虑使用某种类型的Seat类来保存有关预订的信息，例如Passanger指针或类似的东西。

要保留有关多个Passangers的信息，您可以使用类似std :: vector＆lt;的std ::的weak_ptr＆LT;通勤＆GT; ＆GT;

拥有多个轮子 - 类似于std :: array＆lt;轮＆GT; - 座位相同，std :: array＆lt;座椅＆GT;

我的聚合，关联和组合的关系在这个C ++程序中不起作用？

1 个答案: