How to exit...?

Ok, I'm learning C++, and here's the code for a little tic-tac-toe game I've written. At the end, I'd like to be able to provide the user with a choice of yes or no to keep playing, but I have problems telling my app to quit right then and there. Here's the code; please someone show me how to do this!

Code:

---

#include <iostream.h>
#include <stdlib.h>
#include <time.h>

char board[3][3];
int hAxis;
int vAxis;
int lineCheck;
char uRes;
char cWin;
int pTurn = 0;
long xWins = 0;
long oWins = 0;
long cWins = 0;

void endGame(char);
char isWinner();
void mainGame();


void main()
{
srand(time(NULL));
board[0][0] = ' ';
board[0][1] = ' ';
board[0][2] = ' ';
board[1][0] = ' ';
board[1][1] = ' ';
board[1][2] = ' ';
board[2][0] = ' ';
board[2][1] = ' ';
board[2][2] = ' ';
cout << "Welcome to Tic-Tac-Toe!\nYou are player 'X'" << endl;
mainGame();
cout << "\n\nThanks for playing!";
}

void mainGame()
{
        cout << endl << "MainGame" << endl;
        int hComp;
        int vComp;

                do{
                        do{
                                cout << "\n 1 2 3\n" <<
                                "1" << board[0][0] << "|" << board[0][1] << "|" << board[0][2] <<
                                "\n -+-+-\n" <<
                                "2" << board[1][0] << "|" << board[1][1] << "|" << board[1][2] <<
                                "\n -+-+-\n" <<
                                "3" << board[2][0] << "|" << board[2][1] << "|" << board[2][2] << endl << endl;
                               
                                do{
                                        cout << "Enter Horizontal: ";
                                        cin >> hAxis;
                                }while (hAxis > 3 && hAxis < 1);
                                do{
                                        cout << "Enter Vertical: ";
                                        cin >> vAxis;
                                }while (vAxis > 3 && vAxis < 1);
                               
                                if (board[vAxis - 1][hAxis - 1] != ' '){cout << "\nThat space is already occupied by '" << board[vAxis - 1][hAxis - 1] << "'!" << endl;};
                        }while(board[vAxis - 1][hAxis - 1] != ' ');
                       
                        board[vAxis - 1][hAxis - 1] = 'X';

                        cWin = isWinner();
                        if(cWin != ' ') endGame(cWin);
                        else{

                                if (pTurn < 4){
                                do{
                                        hComp = rand() % 3;
                                        vComp = rand() % 3;
                                }while (board[vComp][hComp] != ' ');
                                board[vComp][hComp] = 'O';
                                };
                       
                                cWin = isWinner();
                                if(cWin != ' ') endGame(cWin);
                                else pTurn = pTurn + 1;
                        }
                }while(pTurn < 5);
        endGame(isWinner());
}

char isWinner()
{
        lineCheck = (int)board[0][0] + (int)board[0][1] + (int)board[0][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        lineCheck = (int)board[1][0] + (int)board[1][1] + (int)board[1][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        lineCheck = (int)board[2][0] + (int)board[2][1] + (int)board[2][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
       
        lineCheck = (int)board[0][0] + (int)board[1][0] + (int)board[2][0];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        lineCheck = (int)board[0][1] + (int)board[1][1] + (int)board[2][1];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        lineCheck = (int)board[0][2] + (int)board[1][2] + (int)board[2][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);

        lineCheck = (int)board[0][0] + (int)board[1][1] + (int)board[2][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);

        lineCheck = (int)board[0][2] + (int)board[1][1] + (int)board[2][0];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        return ' ';
}

void endGame(char winner)
{
        cout << "\n 1 2 3\n" <<
        "1" << board[0][0] << "|" << board[0][1] << "|" << board[0][2] <<
        "\n -+-+-\n" <<
        "2" << board[1][0] << "|" << board[1][1] << "|" << board[1][2] <<
        "\n -+-+-\n" <<
        "3" << board[2][0] << "|" << board[2][1] << "|" << board[2][2] << "\n\n";

        switch(cWin)
        {case 'X': cout << "'X' wins the game!"; xWins = xWins + 1; break;
        case 'O': cout << "'O' wins the game!"; oWins = oWins + 1; break;
        case ' ': cout << "It's a cat's game!"; cWins = cWins + 1; break;}
       
        cout << "\n\nScoreboard:\n-----------\nX Wins: " << xWins << "\nO Wins: " << oWins << "\nCat's Games: " << cWins <<
                "\n\nWould you like to play again? (Y/N): ";

        board[0][0] = ' ';
        board[0][1] = ' ';
        board[0][2] = ' ';
        board[1][0] = ' ';
        board[1][1] = ' ';
        board[1][2] = ' ';
        board[2][0] = ' ';
        board[2][1] = ' ';
        board[2][2] = ' ';

        cin >> winner;
        if (uRes != 'Y' || uRes != 'y') //now what?
}

---

Also note that a lot of this code has been written pretty beginner-like, so please feel free to show me other ways of doing this stuff. Please mark code you create or edit by adding //* or something so I will know! Thanks!

Use exit(0).

This code always exits no matter what the user enters:

Code:

---

//This quality application allows you to play Tic-Tac-Toe and not pay attention in class.


#include <iostream.h>
#include <stdlib.h>
#include <time.h>

char board[3][3];
int hAxis;
int vAxis;
int lineCheck;
char uRes;
char cWin;
int pTurn = 0;
long xWins = 0;
long oWins = 0;
long cWins = 0;

void endGame(char);
char isWinner();
void mainGame();


void main()
{
srand(time(NULL));
board[0][0] = ' ';
board[0][1] = ' ';
board[0][2] = ' ';
board[1][0] = ' ';
board[1][1] = ' ';
board[1][2] = ' ';
board[2][0] = ' ';
board[2][1] = ' ';
board[2][2] = ' ';
cout << "Welcome to Tic-Tac-Toe!\nYou are player 'X'" << endl;
mainGame();
cout << "\n\nThanks for playing!";
}

void mainGame()
{
        cout << endl << "MainGame" << endl;
        int hComp;
        int vComp;

                do{
                        do{
                                cout << "\n 1 2 3\n" <<
                                "1" << board[0][0] << "|" << board[0][1] << "|" << board[0][2] <<
                                "\n -+-+-\n" <<
                                "2" << board[1][0] << "|" << board[1][1] << "|" << board[1][2] <<
                                "\n -+-+-\n" <<
                                "3" << board[2][0] << "|" << board[2][1] << "|" << board[2][2] << endl << endl;
                               
                                do{
                                        cout << "Enter Horizontal: ";
                                        cin >> hAxis;
                                }while (hAxis > 3 && hAxis < 1);
                                do{
                                        cout << "Enter Vertical: ";
                                        cin >> vAxis;
                                }while (vAxis > 3 && vAxis < 1);
                               
                                if (board[vAxis - 1][hAxis - 1] != ' '){cout << "\nThat space is already occupied by '" << board[vAxis - 1][hAxis - 1] << "'!" << endl;};
                        }while(board[vAxis - 1][hAxis - 1] != ' ');
                       
                        board[vAxis - 1][hAxis - 1] = 'X';

                        cWin = isWinner();
                        if(cWin != ' ') endGame(cWin);
                        else{

                                if (pTurn < 4){
                                do{
                                        hComp = rand() % 3;
                                        vComp = rand() % 3;
                                }while (board[vComp][hComp] != ' ');
                                board[vComp][hComp] = 'O';
                                };
                       
                                cWin = isWinner();
                                if(cWin != ' ') endGame(cWin);
                                else pTurn = pTurn + 1;
                        }
                }while(pTurn < 5);
        endGame(isWinner());
        mainGame();
}

char isWinner()
{
        lineCheck = (int)board[0][0] + (int)board[0][1] + (int)board[0][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        lineCheck = (int)board[1][0] + (int)board[1][1] + (int)board[1][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        lineCheck = (int)board[2][0] + (int)board[2][1] + (int)board[2][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
       
        lineCheck = (int)board[0][0] + (int)board[1][0] + (int)board[2][0];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        lineCheck = (int)board[0][1] + (int)board[1][1] + (int)board[2][1];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        lineCheck = (int)board[0][2] + (int)board[1][2] + (int)board[2][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);

        lineCheck = (int)board[0][0] + (int)board[1][1] + (int)board[2][2];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);

        lineCheck = (int)board[0][2] + (int)board[1][1] + (int)board[2][0];
        if(lineCheck == 264 || lineCheck == 237) return (char)(lineCheck / 3);
        return ' ';
}

void endGame(char winner)
{
        cout << "\n 1 2 3\n" <<
        "1" << board[0][0] << "|" << board[0][1] << "|" << board[0][2] <<
        "\n -+-+-\n" <<
        "2" << board[1][0] << "|" << board[1][1] << "|" << board[1][2] <<
        "\n -+-+-\n" <<
        "3" << board[2][0] << "|" << board[2][1] << "|" << board[2][2] << "\n\n";

        switch(cWin)
        {case 'X': cout << "'X' wins the game!"; xWins = xWins + 1; break;
        case 'O': cout << "'O' wins the game!"; oWins = oWins + 1; break;
        case ' ': cout << "It's a cat's game!"; cWins = cWins + 1; break;}
       
        cout << "\n\nScoreboard:\n-----------\nX Wins: " << xWins << "\nO Wins: " << oWins << "\nCat's Games: " << cWins <<
                "\n\nWould you like to play again? (Y/N): ";

        board[0][0] = ' ';
        board[0][1] = ' ';
        board[0][2] = ' ';
        board[1][0] = ' ';
        board[1][1] = ' ';
        board[1][2] = ' ';
        board[2][0] = ' ';
        board[2][1] = ' ';
        board[2][2] = ' ';
        pTurn = 0;

        cin >> uRes;
        if (uRes != 'Y' || uRes != 'y') exit(0); else mainGame();
}

---

First of all, I don't recommend using exit(0);. This violates one of the 3 rules of C++. For those who haven't heard them here they are:

1. Don't use global variables
2. Don't use goto statements
3. Every program should have one and only one entrance and exit.

I would structure my endgame function to return a bool. Then return their choice.(as true or false obviously)

Something like this:

void main (void){
//do stuff
MainGame();
}

bool EndGame(){
cin >> answer;
if (answer == 'Y' || answer == 'y')
return true;
return false;
}

MainGame(){
//do stuff
do {
//more suff
}
while EndGame(char);
}

Now if you return false (i.e. they do not wish to continue playing) the program will exit the MainGame function and exit the program normally. No need for the exit(0);

Calling the MainGame function inside the EndGame function will eventually cause a stack overflow (it would take a long time, but it would happen), because you never let the functions return, each call to MainGame would leave an EndGame and MainGame behind it on the stack.

Hope this helps.

Good point - I've never seen those rules before, although they seem very sensible. If I'd spent longer on it, I probably would have used my normal program method which is - only ever have one global function (main).

Code:

---

class MyApp {
public:
    MyApp() { }
    MyApp(int argc, char** argv) { }
    virtual ~MyApp { }

    bool Run() {
        // Set the program going
        // Whole app is controlled from here
        // Usually only returns false, to end,
        // but occasionally returns true, to restart.
    }
}

int main(int argc, char** argv) {
    MyApp theApp(argc, argv);

    while(theApp.Run());
}

---

This is the way a lot of Java programs are written, too.

am I stupid or something but when there done make a message box come up with a yes and no button
then have a case so if the user hit yes it restarts the game no it ends the game

int iResults
iResults = MessageBox("Would you like to exit or play again", "What would you like to do", MB_YESNO | MB_ICONQUESTION)
switch (iResults)
{
case IDYES :
Goto start of code, code
break;
case IDNO :
OnOK();
break;
}

umm ... this is a console app. Meaning, no message boxes.