c++ - 尝试在头文件中私有(private)声明 vector 时出错

Question

嘿，有人建议我在 private(Iventory.h) 中声明我的 vector ，而不是在我已经完成的 .cpp(Inventory.cpp) 中全局声明。但是现在有很多错误向我吐出。

以下是错误:

Error   1   error C2143: syntax error : missing ';' before '<'  c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   22  1   MaroonedCA2
Error   2   error C4430: missing type specifier - int assumed. Note: C++ does not support default-int   c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   22  1   MaroonedCA2
Error   3   error C2238: unexpected token(s) preceding ';'  c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   22  1   MaroonedCA2
Error   4   error C2143: syntax error : missing ';' before '<'  c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   23  1   MaroonedCA2
Error   5   error C4430: missing type specifier - int assumed. Note: C++ does not support default-int   c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   23  1   MaroonedCA2
Error   6   error C2238: unexpected token(s) preceding ';'  c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   23  1   MaroonedCA2
Error   7   error C2143: syntax error : missing ';' before '<'  c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   24  1   MaroonedCA2
Error   8   error C4430: missing type specifier - int assumed. Note: C++ does not support default-int   c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   24  1   MaroonedCA2
Error   9   error C2039: 'const_iterator' : is not a member of '`global namespace'' c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   24  1   MaroonedCA2
Error   10  error C2238: unexpected token(s) preceding ';'  c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.h   24  1   MaroonedCA2
Error   11  error C2065: 'inventory' : undeclared identifier    c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.cpp 18  1   MaroonedCA2
Error   12  error C2228: left of '.push_back' must have class/struct/union  c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.cpp 18  1   MaroonedCA2
Error   13  error C2065: 'inventory' : undeclared identifier    c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.cpp 39  1   MaroonedCA2
Error   14  error C2228: left of '.size' must have class/struct/union   c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.cpp 39  1   MaroonedCA2
Error   15  error C2065: 'inventory' : undeclared identifier    c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.cpp 42  1   MaroonedCA2
Error   16  error C2228: left of '.size' must have class/struct/union   c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.cpp 42  1   MaroonedCA2
Error   17  error C2065: 'inventory' : undeclared identifier    c:\users\conor\documents\college\dkit - year 2 - repeat\dkit - year 2 - semester 1 - repeat\games programming\maroonedca2\maroonedca2\inventory.cpp 43  1   MaroonedCA2

Inventory.h

#ifndef INVENTORY_H
#define INVENTORY_H
#include <string>

using namespace std; 
class Inventory
{
public:
    //Constructor
    Inventory();

    //Methods.
    string add(string item);
    void displayInventory();
    void showInventory();
private:
    //Data members
   vector<string> inventory;
   vector<string>::iterator myIterator;
   vector<string>::const_iterator iter;
    };


#endif //INVENTORY_H

库存.cpp

#include "Inventory.h"
#include <iostream>
#include <vector>   //  To enable the use of the vector class.
#include <string>


using namespace std;



Inventory::Inventory()
{

}

string Inventory :: add(string item)
{
inventory.push_back(item);
return item;
}

void Inventory:: showInventory()
{
char input[80];
    cin >> input;
    char inventoryRequest[] = "i";
    int invent = strcmp (input,inventoryRequest);
    //compare the player input to inventoryRequest (i) to see if they want to look at inventory.
    if(invent == 0)
    {
        displayInventory();
    }


}
void Inventory:: displayInventory()
{
//vector<string> inventory;
    cout<< "You have " << inventory.size() << " items.\n";
    cout << "\n******Inventory******";
    cout<< "\nYour items:\n";
    for (int i= 0; i< inventory.size(); ++i)
        cout<< inventory[i] << endl;
}

Answer 1

您需要包括 <vector>在你的Inventory.h文件。

这与错误无关，但你也应该避免把using namespace std在头文件中。 using namespace否定了拥有 namespace 的优势，通过将它放在 header 中，您可以将它强制应用于包含您的 header 的任何代码。这可能会以神秘的方式破坏代码。就个人而言，我不会使用 using namespace std任何地方。困惑的可能性远远超过(非常适度的)好处。