Unexpected Output using char array in TicTacToe Class - c++

Question

It was pointed out to me here that passing an board array into member functions of a tictactoe class was a bit of bad practice. It makes more sense to make it a private member variable and manipulate it internally without main ever having knowledge of it.
I attempted to implement this change in my code and now i'm receiving very strange character outputs when attempting to print the board to the console:
Image of Output
I have just begun using classes so I imagine that I have made an elementary mistake and it's showing through in this way. Any thoughts?
Main
//implementation of TicTacToe
//Using classes this time
#include <iostream>
#include "TicTacToeClass.h"
int main()
{
//Assumes no play unless user decides they want to play and initializes game variable to TicTacToe class
bool play = false;
TicTacToe game;
play = game.getUserWantToPlay();
//allows for multiple games to be played
while(play == true)
{
char playerWinner = 'n';
char player = 'X';
//single game iteration
while(playerWinner == 'n')
{
game.drawBoard();
game.getPlayerMove(player);
playerWinner = game.checkForWin(player);
if(playerWinner == 'n')
{
player = game.togglePlayer(player);
}
}
game.drawBoard();
play = game.getUserWantToPlay();
}
return(0);
}
Class Header
* TicTacToeClass.h
*
* Created on: Jun 15, 2016
*
*/
#ifndef TICTACTOECLASS_H_
#define TICTACTOECLASS_H_
class TicTacToe
{
public:
bool getUserWantToPlay();
void drawBoard();
void getPlayerMove(char player);
char togglePlayer(char player);
char checkForWin(char player);
private:
char squareArray[9];
};
#endif /* TICTACTOECLASS_H_ */
Class Implementation
//TicTacToe class implementation
//Leeroy Jenkins
#include "TicTacToeClass.h"
#include <iostream>
char squareArray[9] = {'1','2', '3', '4', '5', '6', '7', '8', '9'};
bool TicTacToe::getUserWantToPlay()
{
char response;
bool invalidResponse = true;
bool play = false;
while(invalidResponse == true)
{
std::cout << "Would you like to play a new game of TicTacToe? (y/n) " << std::endl;
std::cin >> response;
if(response == 'y')
{
invalidResponse = false;
play = true;
}
else if(response == 'n')
{
std::cout << "No Problem!";
invalidResponse = false;
}
else
{
std::cout << "Please input a proper response (y/n)" << std::endl;
}
}
return play;
}
void TicTacToe::drawBoard()
{
//draws the game board with updated characters for each player
std::cout << "Player 1 (X) - Player 2 (O)" << std::endl << std::endl << std::endl;
std::cout << " | |" << std::endl;
std::cout << " " << squareArray[0] << " | " << squareArray[1] << " | " << squareArray[2] << std::endl;
std::cout << "____|_____|____" << std::endl;
std::cout << " | | " << std::endl;
std::cout << " " << squareArray[3] << " | " << squareArray[4] << " | " << squareArray[5] << std::endl;
std::cout << "____|_____|____" << std::endl;
std::cout << " | | " << std::endl;
std::cout << " " << squareArray[6] << " | " << squareArray[7] << " | " << squareArray[8] << std::endl;
}
void TicTacToe::getPlayerMove(char player)
{
//Gets player move and stores in board array for display through next iteration
bool playerMoveFound = false;
char playerTurn = '0';
char playerMove = '0';
if(player == 'X')
{
playerTurn = '1';
}
else
{
playerTurn = '2';
}
while(playerMoveFound == false)
{
std::cout << "Player " << playerTurn << " please make a move" << std::endl;
std::cin >> playerMove;
for(int x = 0; x < 9; x++)
{
//If finds the array number makes the change to the iteration...prevents x or o movement
if(playerMove == squareArray[x] && playerMove != 'X' && playerMove != 'O' && playerMove != 'x' && playerMove != 'o')
{
squareArray[x] = player;
playerMoveFound = true;
}
}
if(playerMoveFound == false)
{
std::cout << "Invalid player move..." << std::endl;
}
}
}
char TicTacToe::checkForWin(char player)
{
char playerWin = 'n';
int testForTie = 0;
//Tests winning combinations
if(squareArray[0] == squareArray[1] && squareArray[1] == squareArray[2])
{
playerWin = player;
}
else if(squareArray[0] == squareArray[3] && squareArray[3] == squareArray[6])
{
playerWin = player;
}
else if(squareArray[0] == squareArray[4] && squareArray[4] == squareArray[8])
{
playerWin = player;
}
else if(squareArray[1] == squareArray[4] && squareArray[4] == squareArray[7])
{
playerWin = player;
}
else if(squareArray[2] == squareArray[4] && squareArray[4] == squareArray[6])
{
playerWin = player;
}
else if(squareArray[2] == squareArray[5] && squareArray[5] == squareArray[8])
{
playerWin = player;
}
else if(squareArray[3] == squareArray[4] && squareArray[4] == squareArray[5])
{
playerWin = player;
}
else if(squareArray[6] == squareArray[7] && squareArray[7] == squareArray[8])
{
playerWin = player;
}
else
{
//Tests for a tie game
for(int x = 0; x < 9; x++)
{
if(squareArray[x] == 'x' || squareArray[x] == 'o' || squareArray[x] == 'X' || squareArray[x] == 'O')
{
testForTie++;
}
}
if(testForTie == 9)
{
playerWin = 't';
}
}
if(playerWin == player)
{
if(player == 'X')
{
std::cout << std::endl << "Congratulations player 1! You Win!" << std::endl;
}
else
{
std::cout << std::endl << "Congratulations player 2! You Win!" << std::endl;
}
}
else if(playerWin == 't')
{
std::cout << "Tie! You should play again to settle the duel!" << std::endl;
}
return(playerWin);
}
char TicTacToe::togglePlayer(char player)
{
player = player == 'X' ? 'O':'X';
return(player);
}

Answer 1

It doesn't appear that your TicTacToe class has a constructor that initializes its squareArray class member, your game's board.
char squareArray[9] = {'1','2', '3', '4', '5', '6', '7', '8', '9'};
This declares some variable called squareArray, in the global scope. It does not initialize your class member of the same name, and this doesn't have anything to do with the class's member.
As such, the class member's initial contents consist of uninitialized memory, with random garbage. You're seeing the results of the undefined behavior, displaying the contents of an uninitialized array to std::cout.
You need to have a class constructor that initializes the class member, accordingly.

Answer 2

You never initialized squareArray in TicTacToe which is what
std::cout << " " << squareArray[0] << " | " << squareArray[1] << " | " << squareArray[2] << std::endl;
uses. When you did
char squareArray[9] = {'1','2', '3', '4', '5', '6', '7', '8', '9'};
in the implementation file you make a global char array named squareArray. You do not initialize the class member variable squareArray. You need to write a default constructor that initializes the member variable. You could use
TicTacToe() : squareArray{'1','2', '3', '4', '5', '6', '7', '8', '9'} {}