sharing a static varable across classes

Hello.

I have simple class called Board.hpp and Board.cpp.

I have also a DNBoard.hpp and DNBoard.cpp. I have a static variable in Board.hpp and I set that variable in Board.cpp. I need a static as the variable should have class scope.

However, when I try and access that variable from DNBoard.cpp I get a negative value and not the value that I set in the Board.cpp.

Board.hpp

Code:

class Board
{
public:
static int bHandle(){return _bHandle;}

private:
static int _bHandle;
};

Board.cpp

Code:

int Board::_bHandle = 0; //initialize

void OpenLibrary()
{
     Board::_bHandle = 101023; //Value I want to set and access in DNBoard.cpp

DNBoard.hpp

Code:

#include "Board.hpp"

class DNBoard : public Board
{
  // some stuff here
};

DNBoard.cpp

Code:

void Service()
{
    int handle = Board::bHandle(); //Give an incorrect value here
}

Assuming you've friended OpenLibrary or something that actually allows that access to a private variable to happen, then Service sees 0 before OpenLibrary is called and 101023 after. Since the example you posted works, there's not much more we can say. If you want to post an example that doesn't work, then I guess we can look at that.

hello dude...
_bHandle is private...
if you want to access it in its derived class, use protected...

I guess your code like this:

Code:

#include <stdio.h>;

class Board
{
public:
    static int bHandle(){return _bHandle;}
    void OpenLibrary();

protected:
    static int _bHandle;
};

class DNBoard : public Board
{
public:
    void Service();
};


int Board::_bHandle = 0; //initialize

void Board::OpenLibrary()
{
     Board::_bHandle = 101023; //Value I want to set and access in DNBoard.cpp
}

void DNBoard::Service()
{
    int handle = Board::bHandle(); //Give an incorrect value here
    printf("%i", Board::_bHandle);
}

int main()
{
    Board board;
    board.OpenLibrary();

    DNBoard dnboard;
    dnboard.Service();

}

Am I right?