Question

#include <iostream>
#include <iomanip>
#include <string>

using namespace std;

//In this section I create the class HotelRoom

class HotelRoom
{
protected:
    HotelRoom(){}
    char room_Number[4];
    char* guestName;
    double rate;

public:

    HotelRoom(char Num[], double daily, char* name);
    HotelRoom(const HotelRoom &);
    ~HotelRoom();
    int Get_Capacity();
    int Get_Status();
    double Get_Rate();
    const char* Get_Number();
    const char* Get_Guest();
    int Change_Status(int Stat);
};

HotelRoom::HotelRoom(char Num[], double daily, char* name)
{
    strcpy_s(room_Number, 4, Num);
    guestName = new char[strlen(name) + 1];
    strcpy_s(guestName, 20, name);
    rate = daily;
}
HotelRoom::HotelRoom(const HotelRoom& room_r)
{
    strcpy_s(room_Number, room_r.room_Number);
    guestName = new char[strlen(room_r.guestName) + 1];
    strcpy_s(guestName, 20, room_r.guestName);
    rate = room_r.rate; 
}
HotelRoom::~HotelRoom()
{
    cout << endl << endl;
    cout << "Decunstructor Activated." << endl;
    delete[] guestName;
}

double HotelRoom::Get_Rate()
{
    return rate;
}
const char* HotelRoom::Get_Number()
{
    return room_Number;
}
const char* HotelRoom::Get_Guest()
{
    return guestName;
}
class DerivedGuestRoom : public HotelRoom
{
public:
    DerivedGuestRoom(int max, int stat, int nights);
    DerivedGuestRoom(const DerivedGuestRoom&);
    ~DerivedGuestRoom();

protected:
    int capacity;
    int status = 0; //0 if unoccupied
    int days;

};

DerivedGuestRoom::DerivedGuestRoom(int max, int stat, int nights) :  capacity(max), status(stat), days(nights)
{
    cout << "data members set";
}

DerivedGuestRoom::~DerivedGuestRoom()
{
    cout << "\ndecunstrucor";
}
class DerivedMeetingRoom : public HotelRoom
{
public:
    DerivedMeetingRoom(int seat, int stat);
    DerivedMeetingRoom(const DerivedMeetingRoom&);
    ~DerivedMeetingRoom();

protected:
    int seats;
    int status; //1 if booked for meeting 0 otherwise
};
DerivedMeetingRoom::DerivedMeetingRoom(int seat, int stat) : seats(seat), status(stat)
{
    cout << "data members set";
}

DerivedMeetingRoom::~DerivedMeetingRoom()
{
    cout << "\ndecunstrucor";
}
void Display_info(HotelRoom&);
HotelRoom* Create_Hotel();
int main()
{
    cout << setprecision(2)
        << setiosflags(ios::fixed)
        << setiosflags(ios::showpoint);

    HotelRoom* Hotel_Rooms[200];

    int count = 0;
    char response;

    cout << endl;
    cout << "Do you want to enter information about a hotel room?(Y/N): ";
    response = cin.get();
    cin.get();

    while (toupper(response) == 'Y' && count < 10)
    {
        Hotel_Rooms[count] = Create_Hotel();
        ++count;
        cout << endl;
        cout << "Do you want to enter information about a hotel room?(Y/N): ";
        response = cin.get();
        cin.get();
    }
    //Display the accounts created
    for (int i = 0; i < count; ++i)
        Display_info(*Hotel_Rooms[i]);

    for (int i = 0; i < count; ++i)
        delete Hotel_Rooms[i];

    cout << endl;
    system("PAUSE");
    return 0;
}
void Display_info(HotelRoom& room)
{
    cout << "\n\nGuest's Name: " << room.Get_Guest() << endl << endl;

    cout << "\nYour room number is " << room.Get_Number() << endl << endl;

    cout << "\nDaily rate is: " << room.Get_Rate() << endl << endl;
    cout << endl;
    cout << endl;
}
HotelRoom* Create_Hotel()
{
    //These are the variables that will be holding data then passed through objects

    char roomNumber[4];
    char guestName[20];

    double dailyRate = 89.00;

    HotelRoom* room_ptr;

    //This portion asks for user input

    cout << "\nEnter Guest information\n\n";

    cout << "Enter the room number: ";
    cin.getline(roomNumber, 4);

    cout << "Enter the guest's name: ";
    cin.getline(guestName, 20);
    cout << endl;

    cin.get(); //Clears input buffer

    room_ptr = new HotelRoom(roomNumber, dailyRate, guestName);

    return room_ptr;
}

我拿出了HotelRoom（）;从父类构造函数和我从子类构造函数中删除。我现在只有这个错误：

LearningOOP.exe已触发断点。

我从未遇到过这个，所以不确定它是什么意思。

Answer 1

您尚未为HotelRoom类定义默认构造函数。

class HotelRoom
{
protected:
    char room_Number[4];
    char* guestName;
    double rate;

public:
    HotelRoom(); //< Not defined!
    HotelRoom(char Num[], double daily, char* name);
    HotelRoom(const HotelRoom &);
    ~HotelRoom();
    int Get_Capacity();
    int Get_Status();
    double Get_Rate();
    const char* Get_Number();
    const char* Get_Guest();
    int Change_Status(int Stat);
};

“未解析的外部符号”链接器错误意味着您已在应用程序中声明并使用了一段代码，但在使用之前尚未对其进行定义。

编辑（根据您在下面的跟进评论）：

您无法将构造函数取出，因为代码的其他部分需要它。请在代码中查看此行：

DerivedGuestRoom::DerivedGuestRoom(int max, int stat, int nights) : HotelRoom(), capacity(max), status(stat), days(nights)
//                                                                  ^---------^
//                                                                       |
//                                                            Using the default constructor.

DerivedMeetingRoom::DerivedMeetingRoom(int seat, int stat) : HotelRoom(), seats(seat), status(stat)
//                                                           ^---------^
//                                                                |
//                                                         And again here!

您需要删除实现HotelRoom类的默认构造函数，或者向DerivedMeetingRoom和DerivedGuestRoom类构造函数添加参数，以便您可以使用HotelRoom(char Num[], double daily, char* name)构造

Answer 2

您声明了默认构造函数：

class HotelRoom
{
public:
  HotelRoom();
}

并且没有该默认构造函数方法的实现。您可以更改为：

class HotelRoom
{
public:
  HotelRoom() {}
}

或在cpp文件中实现HotelRoom:HotelRoom { }。

LNK2019和1120是什么错误

2 个答案: