Question

我试图编译我的程序，但我坚持这些错误，我不知道在哪里找到并纠正它。

1>Main.obj : error LNK2005: "int * Coins" (?Coins@@3PAHA) already defined in DisplayErrorMessage.obj
1>Main.obj : error LNK2005: "int * NumCoins" (?NumCoins@@3PAHA) already defined in DisplayErrorMessage.obj
1>Main.obj : error LNK2005: "int * ItemPrice" (?ItemPrice@@3PAHA) already defined in DisplayErrorMessage.obj
1>Main.obj : error LNK2005: "int * NumItems" (?NumItems@@3PAHA) already defined in DisplayErrorMessage.obj
1>MakeSelection.obj : error LNK2005: "int * Coins" (?Coins@@3PAHA) already defined in DisplayErrorMessage.obj
1>MakeSelection.obj : error LNK2005: "int * NumCoins" (?NumCoins@@3PAHA) already defined in DisplayErrorMessage.obj
1>MakeSelection.obj : error LNK2005: "int * ItemPrice" (?ItemPrice@@3PAHA) already defined in DisplayErrorMessage.obj
1>MakeSelection.obj : error LNK2005: "int * NumItems" (?NumItems@@3PAHA) already defined in DisplayErrorMessage.obj
1>ShowMenu.obj : error LNK2005: "int * Coins" (?Coins@@3PAHA) already defined in DisplayErrorMessage.obj
1>ShowMenu.obj : error LNK2005: "int * NumCoins" (?NumCoins@@3PAHA) already defined in DisplayErrorMessage.obj
1>ShowMenu.obj : error LNK2005: "int * ItemPrice" (?ItemPrice@@3PAHA) already defined in DisplayErrorMessage.obj
1>ShowMenu.obj : error LNK2005: "int * NumItems" (?NumItems@@3PAHA) already defined in DisplayErrorMessage.obj
1>c:\users\kanaan\documents\visual studio 2010\Projects\Assign2\Debug\Assign2.exe : fatal error LNK1169: one or more multiply defined symbols found

以下是完整代码：

VendingMachine.h

#include <iostream>
#include <cmath>
#include <string>

using namespace std;

int Denominations = 5;
int const ITEMS = 9;



class VendingMachine {
public:
    void MakeSelection(int NumItems [], int ItemPrice[]);
    int ReturnChange(int change, int Coins[], int NumCoins[]);
    void ShowMenu();
    void DisplayErrorMessage(int error);
    void PrintConfidentialInformation(int Denominations, int Items, int Coins[],
                                      int NumCoins[], int ItemPrice[] , int NumItems[]);

private:
    int selection;
    string code;
    double Each_Item[ITEMS];       //price for each item
};

MakeSelection.cpp

#include "VendingMachine.h"

void VendingMachine::MakeSelection(int NumItems [], int ItemPrice[]) {

    int Coins[] = {100, 50, 20, 10, 5};
    int NumCoins[] = {10, 10, 10, 10, 10}; //assume we have 10 coins of each denomination



    int ItemPrice[ ] = { 75, 120, 120, 100, 150, 95, 110, 50, 120 }; //price in cents
    int NumItems[ ] = { 10, 10, 10, 10, 10, 10, 10, 10, 10 };

    double Total_Price = 0;
    double Item_Total = 0;

    string Product[ITEMS] = {"Water","Coke","Diet Coke","Iced Tea","Swiss Chocolate","Candy",
                             "Chips","Bubble Gum","Turkish Delight"
                            };
    int b = 0;
    int a = 1;

    cout << "Please enter the number of your choice from the menu above. " << endl;

    do {
        cout << "\nEnter the number of product OR End transaction: " << endl;
        cin >> selection;
        cout << "\nYou have selected " <<Product[selection] << endl;

        if(selection >= 1 && selection <= 9) {

            NumItems[selection - 1] = NumItems[selection - 1] - 1;

            if(NumItems[selection - 1] >= 0)
                Total_Price = Total_Price + ItemPrice[selection - 1];

            else {
                int error = 1;
                DisplayErrorMessage(error);         //Item finised
                cout <<selection<< endl;
            }
        }
        else if(selection == 10)
            cout << "\nTransaction Ended" << endl;

        else if(selection == 99) {

            cout << "Enter the code to access maintanance: " <<endl;
            cin >> code;

            while(code != "111") {
                int error = 2;
                DisplayErrorMessage(error);
                cin >> code;
            }

            cout << endl;
            cout << "\t\t\t\t\tSales Report " << endl;
            cout << "==================================================== " << endl;
            cout << endl;
            cout << "Number of each product sold with Income cost: " << endl;
            cout << endl;

            do {
                if(NumItems[b] >= 0) {

                    Each_Item[b] = Each_Item[b] + ItemPrice[b];

                    cout << NumItems[b] << "" << Product[b] << " sold for the total cost of " <<(10 - NumItems [b]) * Each_Item[b]/ 100 <<endl;

                    Total_Price = Total_Price + ((10 - NumItems[b]) * Each_Item[b]/100);
                }
                b++;
            } while(a <= ITEMS);
        }
        else {
            int error = 3;
            DisplayErrorMessage(error);
        }
    } while(selection != 10);
}

你可以使用cpp文件和标题

Answer 1

标题中的

int * Coins;不是您定义全局的方式。这是一个定义。你应该使用

extern int* Coins;

标题中的

并在单个翻译单元（cpp文件）中定义变量。

因为你在所有3个cpp文件中包含了定义的标题，所以符号被多次定义，错误。

Answer 2

在标题文件中使用包含警示：

#ifndef _VENDING_MACHINE_H_
#define _VENDING_MACHINE_H_

//your VendingMachine.h contents

#endif //_VENDING_MACHINE_H_

链接错误：找到一个或多个多重定义的符号

2 个答案: