Tic Tac Toe

TicTacToe.js

'use strict';

var prompt = require('prompt');
prompt.start();

var board = [
    [' ', ' ', ' '],
    [' ', ' ', ' '],
    [' ', ' ', ' '],
    [' ', ' ', ' ']
];

var playerTurn = 'X';

function printBoard() {
    console.log(board[0].join(' | '));
    console.log('---------');
    console.log(board[1].join(' | '));
    console.log('---------');
    console.log(board[2].join(' | '));
}

function horizontalWin() {
    return (board[0][0] === playerTurn && board[0][1] === playerTurn && board[0][2] === playerTurn) ||
        (board[1][0] === playerTurn && board[1][1] === playerTurn && board[1][2] === playerTurn) ||
        (board[2][0] === playerTurn && board[2][1] === playerTurn && board[2][2] === playerTurn);
}

function verticalWin() {
    return (board[0][0] === playerTurn && board[1][0] === playerTurn && board[2][0] === playerTurn) ||
        (board[0][1] === playerTurn && board[1][1] === playerTurn && board[2][1] === playerTurn) ||
        (board[0][2] === playerTurn && board[1][2] === playerTurn && board[2][2] === playerTurn);
}

function diagonalWin() {
    return (board[0][0] === playerTurn && board[1][1] === playerTurn && board[2][2] === playerTurn) ||
        (board[2][0] === playerTurn && board[1][1] === playerTurn && board[0][2] === playerTurn);
}

function checkForWin() {
  if ( horizontalWin() || verticalWin() || diagonalWin() ) {
    console.log('Player ' +  playerTurn + ' Won!'); // announce to the world
    printBoard(); // show the board for bragging rights
    return true;
  }
  return false;
}

function placeMark(row, column) {
    board[row][column] = playerTurn;
}

function getPrompt() {
    printBoard();
    console.log("It's Player " + playerTurn + "'s turn.");
    prompt.get(['row', 'column'], function (error, result) {
        placeMark(parseInt(result.row, 10), parseInt(result.column, 10));
        if (checkForWin()) {
            return;
        }
        playerTurn = playerTurn === 'X' ? 'O' : 'X';
        getPrompt();
    });
}

getPrompt();