How to Access a Dynamic struct from an external function C++? - c++

Question

I'm trying to make a very simple text-based game and I encountered an error when I tried to access a dynamic struct from an external function. I initialized all variables and structs in my header file and declared a dynamic alloc in the main function. But still I got errors. Am I missing something? This is my code.
==================main function "new.cpp"====================
#include <stdlib.h>
#include <iostream>
#include <string>
#include "game.h"
using namespace std;
difficulty _df_1;
player* player_1 = new player[3];
int main()
{
//initialize player stats
player_1->hp = 100;
player_1->life = 3;
player_1->mana = 50;
player_1->player_id = 1;
player_1->level = 1;
player_1->player_name= "emmet";
//..end
int turn=1;
cout << "What is your name? <<<";
getline(cin,player_1->player_name,'\n');
cout << "Choose a difficulty level: [0]Easy [1]Normal [2]Godlike" << endl;
int ch;
cin >> ch;
switch(ch)
{
case 0:
cout << "Scardy Cat chose EASY." << endl;
break;
case 1:
cout << "A really nice way to start. NORMAL" << endl;
break;
case 2:
cout << "Overly Manly Man is playing GODLIKE." << endl;
break;
default: cout << "I wonder how you can play this game if you can even read simple instructions."<< endl;return 0; break;
}
while(turn == 1)
{
char ch;
cout << "What do you want to do now? \n <<<<";
cin >> ch;
cin.ignore(5,'\n');
switch(ch)
{
case 'a': case 'A':
player_stat();
break;
case 'v': case 'V':
cheat_menu();
break;
case 'x': case 'X':
return 0;
break;
case '`':
break;
default: cout << "We were unable to process your request. Please try again" << endl; break;
}
}
delete player_1;
return 0;
}
void cheat_menu()
{
cout << "CHEATERS WILL ROT IN THE DEEPEST DEPTHS OF TARTARUS." << endl;
cout << "Enter Code:" << endl;
string cheat;
getline(cin,cheat,'\n');
if(cheat == "poo")
{
system("sleep 3");
cout << "Cheat Activated.." << endl;
player_1->hp += 1000;
player_1->level += 10;
player_1->mana += 1000;
player_stat();
}
else
{
cout << "Wrong cheat code.." << endl;
}
//system("sleep 3");
//system("clear");
}
==================end main function==============
=======external func "player_stat.cpp"===========
#include <iostream>
#include "game.h"
using namespace std;
void player_stat()
{
cout << "Name: " << player_1->player_name << endl
<< "Hp: " << player_1->hp << endl
<< "Life: " << player_1->life << "\t Mana: " << player_1->mana << endl
<< "Level: " << player_1->level << "\t XP: " << player_1->xp
<< endl;
//system("sleep 3");
//system("clear");
}
==================end external func==============
==========header file "game.h"===================
#ifndef _GAME_
#define _GAME_
#include "player_stat.cpp"
using namespace std;
//function prototypes...
void player_stat();
void cheat_menu();
//structs for player and NPC
struct player
{
string player_name;
int life;
double atk;
double hp;
double mana;
int player_id;
int level;
long int xp;
string weapon_name;
double weapon_damage;
};
enum difficulty {EASY,NORMAL,GODLIKE};
#endif
===========end header file=======================
These are the errors I got. Please don't mind the other left out functions in int main(). :P
In file included from game.h:4
from new.cpp
in function `void player_stat()':
`player_1' undeclared (first use in this function)
(Each undeclared identifier is reported only once for each function it appears in.)
At global scope:
`player*player_1' used prior to declaration

Answer 1

You declare the variable using the extern storage specifier:
extern player* player_1;
This tells the compiler that the player_1 variable is defined somewhere else, and the linker will resolve it later.
Also as I noted you actually allocate three player objects. If you only need one then don't allocate three:
player* player_1 = new player;
However, that's not needed either, declaring a normal non-pointer variable will work just as fine:
player player_1;
Then in the other files you use extern to tell the compiler that the variable is defined somewhere else:
extern player player_1;

Answer 2

add
extern player* player_1;
to game.h
this will make the player_1 variable available across all the modules.
also remove
#include "player_stat.cpp"
you are not supposed to include any cpp files in the header files