Array not Updating in a Function in my tic-tac-toe game

Question

So I am making a tic-tac-toe game in c++. Here is my code so far:


#include <iostream>
#include <cmath>

using namespace std;

char gameboard[3][3]{{'1', '2', '3'}, {'4', '5', '6'}, {'7', '8', '9'}}; //Declares the Global Array for the Board

char turn = 'X';
int column = 0;
int row = 0;


void PrintBoard() { //Displays the board
    
    cout << "    |    |  \n";
    cout << " "<<gameboard[0][0]<<"  | " <<gameboard[0][1]<<"  | " <<gameboard[0][2]<< " \n";
    cout << "____|____|____\n";
    cout << "    |    |    \n";
    cout << " "<<gameboard[1][0]<<"  | " <<gameboard[1][1]<<"  | " <<gameboard[1][2]<< " \n";
    cout << "____|____|____\n";
    cout << "    |    |    \n";
    cout << " "<<gameboard[2][0]<<"  | " <<gameboard[2][1]<<"  | " <<gameboard[2][2]<< " \n";
    cout << "    |    |    \n";
}

void PlaceCounter(int TileNum, char Tile) {
    int LocalRow = 0;
    int LocalColumn = 0;
    LocalRow = (floor(Tile/3))-1;
    LocalColumn = (TileNum - LocalRow) - 1;
    gameboard[LocalRow][LocalColumn] = Tile;
    PrintBoard();
}

void RunTurn(char playerturn) {
    char LocalTurnTile = ' ';
    switch(turn) {
        case 'X':
            cout << "It is X's turn. Enter the number corresponding to the tile you want to select: ";
            cin >> LocalTurnTile;
            PlaceCounter(LocalTurnTile, playerturn);
            break;
        case 'O':
            cout << "It is O's turn. Enter the number corresponding to the tile you want to select: ";
            cin >> LocalTurnTile;
            PlaceCounter(LocalTurnTile, playerturn);
            break;
    }
    
    
}

void GameLoop() {
    RunTurn(turn);
    
}


int main() //Main Function
{
    PrintBoard();
    GameLoop();
}

The issue is, whenever the function Print Board is called upon for the second time, in the function PlaceCounter, in order to update the screen, it doesn't change, and displays the same thing. Here is the output

    |    |  
 1  | 2  | 3 
____|____|____
    |    |    
 4  | 5  | 6 
____|____|____
    |    |    
 7  | 8  | 9 
    |    |    
It is X's turn. Enter the number corresponding to the tile you want to select: 5
    |    |  
 1  | 2  | 3 
____|____|____
    |    |    
 4  | 5  | 6 
____|____|____
    |    |    
 7  | 8  | 9 
    |    |

I don't know what shouldn't be working. The 5 square (center) should update to an X, but it isn't. I am quite new to c++ and need some help. If anyone knows what's going on, I would love your help. I've looked on the internet, and no one has had the same issue as me before. I looked all through the code, and can't seem to put my finger on what isn't working.

You have a typo in `LocalRow = (floor(Tile/3))-1;`, where you want to read `TileNum` for sure. -- BTW, since you are using `int`s, you don't need `floor()`, it leads to unnecessary casts. -- And rethink your formula, consider how indexes in C++ work. — the busybee, Aug 24 '22 at 12:29
[What is a debugger and how can it help me diagnose problems?](https://stackoverflow.com/questions/25385173/what-is-a-debugger-and-how-can-it-help-me-diagnose-problems) — Jesper Juhl, Aug 24 '22 at 12:29
You could have avoided some headache by not bothering with a 2D array at all. The interface you show works perfectly well with a 1D array, and it would make your code easier to manage. I'd also get rid of all the globals and learn about classes. I also see you repeating yourself a few times; don't do that. It can be fixed with either a function, or an extra parameter to the function. — sweenish, Aug 24 '22 at 12:58
`PlaceCounter()` should probably be taking a `char` as its first parameter. — sweenish, Aug 24 '22 at 13:02

score 0 · Accepted Answer · answered Aug 24 '22 at 12:32

Your math is out and you have a typo (wrong variable)

This is the correct code (I'm assuming TileNum has a values from 1 to 9)

LocalRow = (TileNum - 1)/3;
LocalColumn = (TileNum - 1)%3;

Note that when you divide one integer by another you always get another integer, so floor is unnecessary.

Array not Updating in a Function in my tic-tac-toe game

1 Answers1