Getting the "undefined reference to class::function" error on my C++ game.

Question

I am programming this game for a university work and i believe that my code is right, but i keep getting this error and it is keeping me from finishing my work in time. So here's the game board class header:

#include <cstdlib>
#include <iostream>
#include <cmath>
#include <cstdio>

class CMagicAlchemistBoard
{
public:

CMagicAlchemistBoard(void); //  Default Constructor
CMagicAlchemistBoard(const CMagicAlchemistBoard& board); //  Copy Constructor 
~CMagicAlchemistBoard(void ); //  Destructor
void SetupBoard(void);  // Function to setup the board
int GetBoardSpace(int row, int col); // Get the color at row,col

//  Accessor functions to get/set board size information 
int GetColumns(void) const { return m_nColumns; }
void SetColumns(int nColumns)  { m_nColumns = (nColumns >= 6) ? nColumns : 6; }
int GetRows(void) const { return m_nRows; }
void SetRows(int nRows)  { m_nRows = (nRows >= 8) ? nRows : 8; }

void DeleteBoard(void); //  Function to delete the board and free memory
void ExecuteMove(int row, int col);
bool IsGameOver(void) const;  //  Is the game over?
void DrawBoard(void);
bool ValidMove(int row, int col); // Function to see if a move is valid

private:

void CreateBoard(void); //Function to create the board and allocate memory
// Class Data
int** m_arrBoard; // 2D array pointer
//  Board size information
char m_arrChars[10];
int m_nColumns;
int m_nRows;        
};

And here is the .cpp file with only the implementation of the DrawBoard() function:

#include "cmagicalchemistboard.h"
using namespace std;
void CMagicAlchemistBoard::DrawBoard(void)
{
cout << "MAGIC ALCHEMIST" << endl;
cout << "  ";
for(int col = 0; col < m_nColumns; col++){ printf(" ---",col); }
cout << endl;
for(int row = 0; row < m_nRows; row++)
{
    for(int col = 0; col < m_nColumns; col++)
    {
        cout << "|  " << m_arrChars[GetBoardSpace(row, col)];
    }
    cout << "| " << endl; 
} 
}

I pretend to use this function on another class. Here's the header of that class:

#include "cmagicalchemistboard.h"
#include <iostream>
#include <cstdlib>
#include <conio.h> //Contains the function getch(), which reads the input from the     keyboard
#define LEFT_ARROW  75
#define RIGHT_ARROW  77
#define UP_ARROW 72
#define DOWN_ARROW 80
#define ESC 27

class CMagicAlchemist
{
public:
    CMagicAlchemist();
    ~CMagicAlchemist();
     // Functions for accessing the game board
    char GetBoardSpace(int row, int col) { return m_board->GetBoardSpace(row,     col); }
    void SetupBoard(void)         { m_board->SetupBoard(); }
    int GetColumns(void)          { return m_board->GetColumns(); }
    void SetColumns(int nColumns) { m_board->SetColumns(nColumns); }
    int GetRows(void)             { return m_board->GetRows(); }
    void SetRows(int nRows)       { m_board->SetRows(nRows); }
    void DeleteBoard(void)        { m_board->DeleteBoard(); }
    bool IsGameOver()             { return m_board->IsGameOver(); }
    void InputGameParameters();
    void GetMove(int &row, int &col);
    void DrawBoard();
    void NewGame();
    void Game();


private:
    CMagicAlchemistBoard* m_board; // Instance of the game board
    int m_nmoves;
};

And finally, the .cpp file of this last class with only the implementation of the function that calls the DrawBoard() function:

#include "cmagicalchemist.h"
void CMagicAlchemist::Game()
{
int x,y;
InputGameParameters();
NewGame();
DrawBoard();
}

So, my problem is: when i compile this program im getting this error: "undefined reference to CMagicAlchemist::DrawBoard()". This is stupid because the DrawBoard() function doesnt even belong to CMagicAlchemist class but instead, it belong to CMagicAlchemistBoard class. Can somebody help me?

Answer 1

You have DrawBoard declared in your CMagicAlchemist class. You call DrawBoard from a CMagicAlchemist member function.

That tries to call Drawboard for the CMagicAlchemist class.