TicTacToe using 2D array in java

Question

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    
    char[][] board = {
        {'?','?','?'},
        {'?','?','?'},
        {'?','?','?'}
    };
    
    System.out.print("Type any key to play the game and type 'n' to stop the game: ");
    String Stop = sc.nextLine();
    while(true){ 
        if(Stop.equals("n"))break;
            System.out.print("Player" + "[" + "X" + "]: ");
            int PlayerX = sc.nextInt();            
           
            if(PlayerX == 1){
                board[2][0] = 'x';
            }
            if(PlayerX == 2){
                board[2][1] = 'x';
            }
            if(PlayerX == 3){
                board[2][2] = 'x';
            }
            if(PlayerX == 4){
                board[1][0] = 'x';
            }
            if(PlayerX == 5){
                board[1][1] = 'x';
            }
            if(PlayerX == 6){
                board[1][2] = 'x';
            }
            if(PlayerX == 7){
                board[0][0] = 'x';
            }
             
            if(PlayerX == 8){
                board[0][1] = 'x';
            }
            if(PlayerX == 9){
                board[0][2] = 'x';
            }
            
            for(char[] x1 : board){
                for(char x2 : x1){
                    System.out.print(x2 + "\t");
                }
                System.out.println();
            }
                       
            System.out.print("Player" + "[" + "O" + "]: ");
            int PlayerO = sc.nextInt();
            
            if(PlayerO == 1){
                board[2][0] = 'o';
            }
            if(PlayerO == 2){
                board[2][1] = 'o';
            }
            if(PlayerO == 3){
                board[2][2] = 'o';
            }
            if(PlayerO == 4){
                board[1][0] = 'o';
            }
            if(PlayerO == 5){
                board[1][1] = 'o';
            }
            if(PlayerO == 6){
                board[1][2] = 'o';
            }
            if(PlayerO == 7){
                board[0][0] = 'o';
            }
            if(PlayerO == 8){
                board[0][1] = 'o';
            }
            if(PlayerO == 9){
                board[0][2] = 'o';
            }
            
            for(char[] x1 : board){
                for(char x2 : x1){
                    System.out.print(x2 + "\t");
                }
                System.out.println();
            }
        } 
    }
}

I am trying to make a simple TicTacToe program in Java. I am already done in placing the X and O, but I am struggling on checking if there is a winner.

I am confused on what code I will type to check the winner of the program.

I have tried using if statement but I don't know what conditions to make — chard bermundo, Feb 19 '23 at 09:51
I am trying to make a tictactoe program by just using 2D array and if statement for checking the winner — chard bermundo, Feb 19 '23 at 09:55
its not about being a newbie in java or not. its about how well you understand how tic tac toe should work, and how well you can translate that into logic. ie checking all rows for a winner, then checking all columns, then checking all diagonals — experiment unit 1998X, Feb 19 '23 at 10:29
I know the logic of tictactoe but I can't translate it into code — chard bermundo, Feb 19 '23 at 10:42

score 1 · Answer 1 · edited Feb 19 '23 at 19:48

You simply just need to write some code to check if there are 3 matches in each row column and diagonal.

You can utilise for loops to do this more efficiently

public static char checkWinner(char[][] board) {
    // Check rows
    for (int i = 0; i < 3; i++) {
        if (board[i][0] != '?' && board[i][0] == board[i][1] && board[i][1] == board[i][2]) {
            return board[i][0];
        }
    }

    // Check columns
    for (int j = 0; j < 3; j++) {
        if (board[0][j] != '?' && board[0][j] == board[1][j] && board[1][j] == board[2][j]) {
            return board[0][j];
        }
    }

    // Check diagonal
    if (board[0][0] != '?' && board[0][0] == board[1][1] && board[1][1] == board[2][2]) {
        return board[0][0];
    }

    // Check anti-diagonal
    if (board[0][2] != '?' && board[0][2] == board[1][1] && board[1][1] == board[2][0]) {
        return board[0][2];
    }

    // No winner
    return '?';
}

If you havent come accross for loops yet, there are plenty of good tutorials out there such as https://www.w3schools.com/java/java_for_loop.asp

(Note, you can also use loops to clean up some of your pre-existing code)

TicTacToe using 2D array in java

1 Answers1