Problems grasping .h files...

Decided to make a RPG Adventure game using Allegro and C++ and I want to split my files up. Here's what I would want them to do.

main.cpp

Code:

#include "player_class.cpp"
#include <allegro.h>

int main(){
  allegro_init();
  return 0;}
END_OF_MAIN();

player_class.cpp

Code:

#include "player_stats.hpp"

int class_setup(int player_class){
  player_class = 1;
  return player_class;}

player_class = class_setup(player_class);

player_stats.hpp

Code:

int player_class = 0;

That's the jist of what I want, but I get errors when compiling it. I'm just wondering why that is and how to fix it?

What are the error messages?

Why is player_class is a global variable?

Why do you include a source file in another source file?

Yeah, you're doing a large number of things wrong. Here's the right way to do it:

Code:

//main.cpp
#include "player.h"
#include <allegro.h>
#include <iostream>

int main()
{
  allegro_init();
  Player protagonist(1); //the main player 
  protagonist.setClass(2);//change the class
  protagonist.getClass(); //access the class
  return 0;
}
END_OF_MAIN();

Code:

//player.cpp
#include "player.h"

Player::Player(int pClass): pClass(pClass){
}

void Player::setClass(int pClass){
    this->pClass = pClass;
}
int Player::getClass() const{
  return pClass;
}

Code:

//player.h
#ifndef PLAYER_H
#define PLAYER_H

class Player{
  private:
    int pClass;
  public:
    Player(int pClass);
    void setClass(int pClass);
    int getClass() const;
};

#endif

Better if you can understand this than jimmy your code to compile. I'm doing a lot of things differently, but each for a reason.

Originally Posted by King Mir

Yeah, you're doing a large number of things wrong. Here's the right way to do it:

Code:

//main.cpp
#include "player.h"
#include <allegro.h>
#include <iostream>

int main()
{
  allegro_init();
  Player protagonist(1); //the main player 
  protagonist.setClass(2);//change the class
  protagonist.getClass(); //access the class
  return 0;
}
END_OF_MAIN();

Code:

//player.cpp
#include "player.h"

Player::Player(int pClass): pClass(pClass){
}

void Player::setClass(int pClass){
    this->pClass = pClass;
}
int Player::getClass() const{
  return pClass;
}

Code:

//player.h
#ifndef PLAYER_H
#define PLAYER_H

class Player{
  private:
    int pClass;
  public:
    Player(int pClass);
    void setClass(int pClass);
    int getClass() const;
};

#endif

Better if you can understand this than jimmy your code to compile. I'm doing a lot of things differently, but each for a reason.

I think I get it now. We're setting things up in "classes" and that's why I'm getting weird errors with the constructors and deconstructurers.

I have one more question. What's the point of ifndef?

Thanks for the advice by the way! ;]

Originally Posted by FoFGhost

I think I get it now. We're setting things up in "classes" and that's why I'm getting weird errors with the constructors and deconstructurers.

I have one more question. What's the point of ifndef?

Thanks for the advice by the way! ;]

Glad it's clear, cause I was expecting to do a lot of explaining.

The include gaurds as they are called make it so that you can include the same header file more than once in the same translation unit. Header files can #include classes that the depend on, and source file can include all the headers that they depend on. This can cause the same file to be included twice. Include gaurds prevent this from being a problem.

Never mind! Fixed a simple typo! Ha ha.

I forgot to include my header file in main instead of the .cpp file! ;D

I changed your code you gave me a little bit and it still runs great, for now. Lol.

Code:

//main.cpp
#include "player_stats.hpp"
#include <iostream>
#include <allegro.h>

int main(){
  allegro_init();

  Player protagonist;
  protagonist.setClass(0);
  
  Player player;
  player.setClass(1);

  std::cout << protagonist.getClass() << "\n\n";
  std::cout << player.getClass() << "\n\n";
  std::cin.get();

  return 0;}
END_OF_MAIN();

Code:

//player_class.cpp
#include "player_stats.hpp"
  
void Player::setClass(int pClass){
  this -> pClass = pClass;}

int Player::getClass() const{
  return pClass;}

Code:

//player_stats.hpp
//#ifndef PLAYER_H
//#define PLAYER_H

class Player{
  private:
    int pClass;
  public:
    void setClass(int pClass);
    int getClass() const;};

//#endif

I commented those out so I can think more on taking them out. Tell me what you think though! ;]

Code:

int Player::getClass() const{
  return pClass;}

Don't do that. Many people would argue this is bad style.
Put it on a new line instead.