#include in header and in main file (c++)

Question

I have a project where there is a class item in a header item.h. I need to use the item class in both my main.cpp file and my player.h header.

There are example files to explain my situation :

main.cpp:

#include "player.h"
#include "item.h"
#include <vector>

std::vector<Item> items;

int main(){
    Item i;
    Player p;
    p.move(10);
    i.ID = 10;
    return 0;
};

player.h:

#include "item.h"
#include <vector>

class Player{
    public:
        std::vector<Item> inventory;
        int x;
        void move(int i){x += i};
};

item.h:

#include <string>

class Item{
    public:
        int ID;
        std::string name;
};

It may contain errors as I didn't compiled it, and just wrote it for you to understand my situation. In my real project, I get errors for redefinition of the Item class. I'm new to C++.

Answer 1

You need to do this in item.h:

#ifndef SOME_WORD
#define SOME_WORD // the same as above
//item.h content
#endif

You can now import item.h in all the files that you want.