freeCodeCamp : Build a Tic Tac Toe Game

In this example below you will see how to do a freeCodeCamp : Build a Tic Tac Toe Game with some HTML / CSS and Javascript

Forked from Chris Dziewa's Pen

Thumbnail
This awesome code was written by freeCodeCamp, you can see more from this user in the personal repository.
You can find the original code on Codepen.io
Copyright freeCodeCamp ©

Technologies

  • HTML
  • CSS
  • JavaScript
<!DOCTYPE html>
<html lang="en" >

<head>
  <meta charset="UTF-8">
  <title>freeCodeCamp : Build a Tic Tac Toe Game</title>
  <link href='https://fonts.googleapis.com/css?family=Architects+Daughter' rel='stylesheet' type='text/css'>

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.4.0/css/font-awesome.min.css">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/normalize/5.0.0/normalize.min.css">

  
      <link rel="stylesheet" href="css/style.css">

  
</head>

<body>

  <div class="outer-container">
  <button class="hard-reset">Reset All</button>
  <p class="score-1"><span class="points"></span><span class="name"></span></p>
  <i class="points-divider">&#124;</i>
  <p class="score-2"><span class="points"></span><span class="name"></span></p>
  <div class="player-one-turn">
    <p></p>
  </div>
  <div class="player-two-turn">
    <p></p>
  </div>
  <div class="board-container">
    <div class="game-starter">
        <p>Would you like to be X or O?</p>
        <button class="choose-x">X</button>
        <button class="choose-o">O</button>
        <button class="back-button"><i class="fa fa-arrow-left"></i> Back</button>
      </div>
      <div class="game-choice">
        <p>How do you want to play?</p>
        <button class="one-player">One Player</button>
        <button class="two-player">Two Player</button>
      </div>
    <div class="game-board">
      <div class="draw-message">
        <p>It was a draw..</p>
      </div>
      <div class="lose-message">
        <p>Uh oh, you lost..</p>
      </div>
      <div class="win-message">
        <p>You Won!!! :)</p>
      </div>
      <canvas id="myCanvas"></canvas>
      <ul class="boxes">
      </ul>
    </div>
  </div>
</div>
  <script src='http://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js'></script>

  

    <script  src="js/index.js"></script>




</body>

</html>

/*Downloaded from https://www.codeseek.co/freeCodeCamp/freecodecamp-build-a-tic-tac-toe-game-KzXQgy */
body,
html {
  width: 100%;
  height: 100%;
}

li {
  list-style: none;
}

.outer-container {
  background: rgba(240,180,135,1);
  box-shadow: inset -1px 1px 7px rgba(0,0,0,.2), inset 1px -1px 7px rgba(0,0,0,.2), 1px 12px 5px rgba(0,0,0,.4), 4px 3px 8px rgba(0,0,0,.4), 5px 10px 10px rgba(0,0,0,.2), -5px 10px 10px rgba(0,0,0,.4);
  position: relative;
  border-radius: 10px;
  width: 400px;
  height: 390px;
  margin: 10% auto;
  padding: 40px 0 0;
}


.board-container {
  width: 350px;
  height: 350px;
  background: rgba(40,40,40,1)
    -webkit-radial-gradient(center, rgba(40,80,60,1), rgba(0,20,20,.6));
  background: rgba(40,40,40,1)
    -moz-radial-gradient(center, rgba(40,80,60,1), rgba(0,20,20,.6));
  background: rgba(40,40,40,1)
    -ms-radial-gradient(center, rgba(40,80,60,1), rgba(0,20,20,.6));
  background: rgba(40,40,40,1)
    radial-gradient(center, rgba(40,80,60,1), rgba(0,20,20,.6));
  background-size: cover;
  position: relative;
  margin: 0 auto;
  overflow: hidden;
}

.game-board {
  width: 100%;
  height: 100%;
  margin: 0 auto;
  position: relative;
}

.boxes {
  padding: 0;
  width: 100%;
  height: 100%;
  position: relative;
  left: 12px;
  top: 0;
}

.boxes li {
  width: 30%;
  height: 30%;
  display: inline-block;
  position: relative;
  z-index: 1000;
  margin-left: 2px;
  margin-right: 2px;
  overflow: hidden;
}

li i {
  font-size: 6.5rem;
  text-align: center;
  display: block;
  width: 100%;
  height: 100%;
  font-style: normal;
  font-family: "Architects Daughter", "Helvetica", "sans-serif";
  color: rgba(220,220,220,.7);
  z-index: 500;
}

li span {
  position: relative;
  bottom: 15px;
}

/* Canvas Drawing */

#myCanvas {
  width: 330px;
  height: 330px;
  position: absolute;
  z-index: 0;
  left: 10px;
  top: 0;
  opacity: 0;
}

/* Player/Computer prompt */
.player-one-turn {
  background: rgba(0,200,200,1);
  left: 15px;
}

.player-two-turn {
  background: rgba(200,100,100,1);
  right: 15px;
}

.player-one-turn,
.player-two-turn {
  position: absolute;
  top: 0;
  width: 170px;
  height: 50px;
  z-index: -10;
  color: white;
  text-align: center;
}

.player-one-turn p,
.player-two-turn p {
  font-size: 1.3rem;
  margin-top: 10px;
}

/* Score keeping */
.points-divider,
.score-1,
.score-2 {
  position: absolute;
  font-size: .9rem;
  margin: 0;
  display: none;
}

.score-1,
.score-2 {
  font-family: 'Architects Daughter', sans-serif;
  top: 17px;
  color: rgba(100,60,50,.8);
}

.score-1 .points, 
.score-2 .points {
  position: absolute;
  text-align: center;
  bottom: 14px;
  color: rgba(100,60,50, .9);
  font-family: 'Architects Daughter', sans-serif;
}

.points-divider {
  top: 5px;
  left: 141px;
  font-size: 2rem;
  font-family: helvetica, sans-serif;
  font-style: normal;
  opacity: .2;
}

.score-1 {
  left: 75px;
}

.score-2 {
  left: 161px;
}

/* reset button */
.hard-reset {
  position: absolute;
  top: 5px;
  right: 20px;
  background: none;
  border: none;
  font-family: 'Architects Daughter', sans-serif;
  color: rgba(100,60,50,.8);
  font-size: 1.1rem;
  border-radius: 20px;
  border: 2px dashed transparent;
  display: none;
}

.hard-reset:hover {
  border: 2px dashed rgba(100,60,50,1);
  color: rgba(100,60,50,1);
}

.hard-reset:focus {
  outline: none;
}

/*  Result Feedback */
span.rotate {
  color: rgba(0,200,200,1);
}

i.win {
  background: black;
}

.draw-message,
.lose-message,
.win-message {
  background: rgba(0,0,0,.8);
  width: 400px;
  height: 400px;
  z-index: 2000;
  position: absolute;
  display: none;
  top: -15px;
  left: 0;
  box-sizing: border-box;
}

.draw-message p,
.lose-message p,
.win-message p {
  color: white;
  text-align: center;
  position: absolute;
  font-size: 2.3rem;
  margin: 0;
  top: 150px;
  left: 50px;
  font-family: 'Architects Daughter', sans-serif;
}

/*============================================
          Game Starter
============================================*/

.game-choice,
.game-starter {
  background: rgba(40,40,40,1)
    -webkit-radial-gradient(center, rgba(40,80,60,1), rgba(0,20,20,.6));
  background: rgba(40,40,40,1)
    -moz-radial-gradient(center, rgba(40,80,60,1), rgba(0,20,20,.6));
  background: rgba(40,40,40,1)
    -ms-radial-gradient(center, rgba(40,80,60,1), rgba(0,20,20,.6));
  background: rgba(40,40,40,1)
    radial-gradient(center, rgba(40,80,60,1), rgba(0,20,20,.6));
  
  display: block;
  width: 100%;
  height: 500px;
  position: absolute;
  top: 0px;
  text-align: center;
  font-family: 'Architects Daughter', Helvetica, sans-serif;
  z-index: 1500;
/*  display: none;*/
}

.game-starter {
  display: none;
}

.game-choice p,
.game-starter p {
  font-size: 2.2rem;
}

.game-choice button,
.game-choice p,
.game-starter button,
.game-starter p {
  color: rgba(220,220,220,1);
  position: relative;
  top: 50px;
  margin: 10px auto;
}

.game-choice p,
.game-starter p {
  max-width: 80%;
}

.game-choice button,
.game-starter button {
  background: none;
  border: none;
  opacity: .6;
  border-radius: 20px;
  border: 2px solid transparent;
  font-size: 1.7rem;
}

.game-starter button {
   font-size: 2.8rem;
}

.game-choice button:focus,
.game-starter button:focus {
  outline: none;
}
.game-choice button:hover,
.game-starter button:hover {
  opacity: 1;
  border: 2px dashed rgba(230,230,230,.5);
}

.game-starter button.back-button  {
  position: absolute;
  top: 270px;
  right: 130px;
  font-size: 1.5rem;
  border: none;
}

.game-starter .back-button:hover {
  border: none;
}

button {
  cursor: pointer;
}

/*============================
    Win/Lose animation 
==============================*/
.rotate {
  -webkit-animation: rotating 2s linear infinite;
  -moz-animation: rotating 2s linear infinite;
  -ms-animation: rotating 2s linear infinite;
  -o-animation: rotating 2s linear infinite;
  animation: rotating 2s linear infinite;
}

@-webkit-keyframes rotating /* Safari and Chrome */ {
  from {
    -ms-transform: rotateY(0deg);
    -moz-transform: rotateY(0deg);
    -webkit-transform: rotateY(0deg);
    -o-transform: rotateY(0deg);
    transform: rotateY(0deg);
  }
  to {
    -ms-transform: rotateY(360deg);
    -moz-transform: rotateY(360deg);
    -webkit-transform: rotateY(360deg);
    -o-transform: rotateY(360deg);
    transform: rotateY(360deg);
  }
}
@keyframes rotating {
  from {
    -ms-transform: rotateY(0deg);
    -moz-transform: rotateY(0deg);
    -webkit-transform: rotateY(0deg);
    -o-transform: rotateY(0deg);
    transform: rotateY(0deg);
  }
  to {
    -ms-transform: rotateY(360deg);
    -moz-transform: rotateY(360deg);
    -webkit-transform: rotateY(360deg);
    -o-transform: rotateY(360deg);
    transform: rotateY(360deg);
  }
}

/*Downloaded from https://www.codeseek.co/freeCodeCamp/freecodecamp-build-a-tic-tac-toe-game-KzXQgy */
/* 
using timeouts with loops
http://stackoverflow.com/questions/25311892/cleartimeout-for-settimeout-in-for-loop
*/

var MYAPP = MYAPP || {
  gameInPlay: false,
  winCombos: [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9],
    [1, 4, 7],
    [2, 5, 8],
    [3, 6, 9],
    [1, 5, 9],
    [7, 5, 3]
  ],
  playerOneScore: 0,
  playerTwoScore: 0,
  timeOuts: [],
  initializeVars: function() {
    this.numFilledIn = 0;
    this.currentBoard = {
      1: '',
      2: '',
      3: '',
      4: '',
      5: '',
      6: '',
      7: '',
      8: '',
      9: ''
    };
  },
  initializeGame: function() {
    MYAPP.initializeVars();
    MYAPP.display.drawBoard();
    $('.game-choice button').click(function() {
      MYAPP.secondPlayer = MYAPP.game.gameSelection(this);
      MYAPP.display.hideGameChoice();
      MYAPP.display.showGameStarter(MYAPP.secondPlayer);
      $('.game-starter .choose-x, .game-starter .choose-o').off().click(MYAPP.game.firstGame);

      $('.back-button').on('click', function() {
        MYAPP.display.hideGameStarter();
        MYAPP.display.showGameChoice();
      });
    });
    $('.hard-reset').on('click', MYAPP.game.resetGame);
  }
};

  /*=========================
      Display functions
==========================*/
MYAPP.display = {  
  hideGameStarter: function() {
  $('.game-starter').fadeOut();
},

  showGameStarter: function(isTwoPlayer) {
  var message;
  if (isTwoPlayer) {
    message = "Player 1 : Would you like X or O?"
  }
  else {
    message = "Would you like to be X or O?";
  }
  MYAPP.timeOuts.push(
    setTimeout(function() {
      $('.game-starter').fadeIn(500).children('p').text(message);
  }, 700));
},

  showGameChoice: function() {
  $('.game-choice').fadeIn(600);
},

  hideGameChoice: function() {
  $('.game-choice').fadeOut(600);
},

  showPlayerOnePrompt: function() {
  if (MYAPP.secondPlayer) {
    $('.player-one-turn p').text('Go Player 1!');
  }
  else {
    $('.player-one-turn p').text('Your turn!');
  }
  $('.player-one-turn').animate({'top': '-45px'}, 500);
},

  hidePlayerOnePrompt: function() {
  $('.player-one-turn').animate({'top': '0'}, 500);
},

  showPlayerTwoPrompt: function() {
  if (MYAPP.secondPlayer) {
    $('.player-two-turn p').text('Go Player 2!');
  }
  else {
    $('.player-two-turn p').text('Computer\'s turn');
  }
  $('.player-two-turn').animate({'top': '-45px'}, 500);
},

  hidePlayerTwoPrompt: function() {
  $('.player-two-turn').animate({'top': '0'}, 500);
},

  showDrawMessage: function() {
  MYAPP.timeOuts.push(
    setTimeout(function() {
    $('.draw-message').fadeIn(500);
  }, 1500));
},

  hideDrawMessage: function() {
  $('.draw-message').fadeOut(1000);
},

  showLoseMessage: function() {
    MYAPP.timeOuts.push(
      setTimeout(function() {
    $('.lose-message').fadeIn(500);
}, 1500)
    );
},

  hideLoseMessage: function() {
  $('.lose-message').fadeOut(1000);
},

  showWinMessage: function() {
    MYAPP.timeOuts.push(
      setTimeout(function() {
    $('.win-message').fadeIn(500).children('p').text("Player " + MYAPP.turn + " wins!! :D ")
}, 1500));
},

  hideWinMessage: function() {
  $('.win-message').fadeOut(1000);
},

  drawBoard: function() {
    MYAPP.timeOuts.push(setTimeout(function() {
    var c = document.getElementById("myCanvas");
    var canvas = c.getContext("2d");
    canvas.lineWidth = 1;
    canvas.strokeStyle = "#fff";
    //vertical lines
    canvas.beginPath();
    canvas.moveTo(100, 0);
    canvas.lineTo(100, 146.5);
    canvas.closePath();
    canvas.stroke();
    canvas.beginPath();
    canvas.moveTo(200, 0);
    canvas.lineTo(200, 146.5);
    canvas.closePath();
    canvas.stroke();

    // horizontal lines
    canvas.lineWidth = .5;

    canvas.beginPath();
    canvas.moveTo(4, 48.5);
    canvas.lineTo(296, 48.5);
    canvas.closePath();
    canvas.stroke();
      
    canvas.beginPath();
    canvas.moveTo(4, 98.5);
    canvas.lineTo(296, 98.5);
    canvas.closePath();
    canvas.stroke();  
  }, 1500));
},

  resetSquares: function() {
  $('.boxes').html('');
  for (var i = 1; i <= 9; i++) {
    var box = '<li class="' + i + '"><i class="letter"><span></span></i></li>';
    $(box).appendTo($('.boxes'));
  }
},
  
  showScore: function() {
    if (MYAPP.secondPlayer) {
      $('.score-1').children('.name').text('player 1'); 
      $('.score-2').children('.name').text('player 2'); 
    }
    else {
      $('.score-1').children('.name').text('player 1'); 
      $('.score-2').children('.name').text('computer'); 
    }
    $('.score-1, .score-2').children('.points').text('0');
    $('.score-1,.score-2, .points-divider').fadeIn();
  },
  updateScore: function(turn) {
    var currentScore = turn === 1 ? MYAPP.playerOneScore : MYAPP.playerTwoScore;

    $('.score-' + turn).children('.points').text(currentScore);
  }
};

/*=========================
      Game Logic
==========================*/
MYAPP.game = {
  whoStarts: function() {
    var random = Math.floor(Math.random() * 2 + 1);
    return random;
  },
  gameSelection: function(item) {
    if ($(item).text() === 'One Player') {
      // returns what secondPlayer value to set
      return false;
    }
    else {
      return true;
    } 
  },
  firstGame: function() {
    MYAPP.playerOneSymbol = $(this).text();
    MYAPP.playerTwoSymbol = MYAPP.playerOneSymbol == 'X' ? 'O' : 'X'; 
    MYAPP.turn = MYAPP.game.whoStarts();
    MYAPP.display.hideGameStarter();
    $('#myCanvas').animate({'opacity': '1'}, 1200);
    $('.hard-reset').fadeIn(600);
    MYAPP.display.showScore();
    MYAPP.display.resetSquares();
    MYAPP.game.play();
  },
  play: function() {
    
    MYAPP.gameInPlay = true;
    $('.boxes li').on('click', function() {
     MYAPP.game.playerTurn(this);
    });  
    
    MYAPP.timeOuts.push(
      setTimeout(function(){
      if (MYAPP.turn === 1) {
        MYAPP.display.showPlayerOnePrompt();
      }
      else if (MYAPP.turn === 2) {
        MYAPP.display.showPlayerTwoPrompt();
      }
    }, 1500),
    setTimeout(function() {
      if (MYAPP.turn === 2 && !MYAPP.secondPlayer) {
        MYAPP.game.computerPlay();
      }
    }, 1200));
  },
  playerTurn: function(square) {
    var symbol = MYAPP.turn === 1 ? MYAPP.playerOneSymbol : MYAPP.playerTwoSymbol;
    var box = $(square).children('i').children('span');
    if (box.text() === '' && MYAPP.gameInPlay && (MYAPP.turn === 1 || (MYAPP.turn === 2 && MYAPP.secondPlayer))) {
      box.text(symbol);
      var number = $(square).attr('class');
      MYAPP.game.updateSquare(number, symbol);
      MYAPP.game.endTurn(symbol);
    }
  },
  computerPlay: function() {
    var computer = MYAPP.computer;
    //test computer move suggestion
    var boxNumber;
    if (computer.computerWhichMove(MYAPP.game) && MYAPP.turn === 2) {
      boxNumber = computer.computerWhichMove(MYAPP.game);
      var currentBox = $('.' + boxNumber).children('i');
      
      var symbol = MYAPP.playerTwoSymbol;

      MYAPP.timeOuts.push(
        setTimeout(function() {
        currentBox.children('span').text(symbol);
        MYAPP.game.updateSquare(boxNumber, MYAPP.playerTwoSymbol);
        MYAPP.game.endTurn(symbol);
      }, 1000));
    } 
  },
  endTurn: function(symbol) {
    MYAPP.numFilledIn = MYAPP.numFilledIn + 1;
    if (MYAPP.gameInPlay) {
      if (MYAPP.game.checkWin(symbol)[0]) {
        MYAPP.game.updateScore(MYAPP.turn);
        if (MYAPP.secondPlayer) {
          MYAPP.display.showWinMessage();
        }
        else {
          MYAPP.turn === 1 ? MYAPP.display.showWinMessage() : MYAPP.display.showLoseMessage();
        }
        MYAPP.gameInPlay = false;
        MYAPP.game.showWinningCombination();
        MYAPP.display.hidePlayerOnePrompt();
        MYAPP.display.hidePlayerTwoPrompt();
        MYAPP.game.reset();
      }
      // stop if it is a draw
      else if (MYAPP.numFilledIn >= 9) {
        MYAPP.gameInPlay = false;
        MYAPP.display.hidePlayerOnePrompt();
        MYAPP.display.hidePlayerTwoPrompt();
        MYAPP.display.showDrawMessage();
        MYAPP.turn = MYAPP.game.whoStarts();
        MYAPP.game.reset();
      } else {
        if (MYAPP.turn === 1) {
          MYAPP.display.hidePlayerOnePrompt();
          MYAPP.display.showPlayerTwoPrompt();
          MYAPP.turn = 2;
          // call computer turn if no second player
          if (!MYAPP.secondPlayer) {
            MYAPP.game.computerPlay();
          }
        } else if (MYAPP.turn === 2) {
          MYAPP.display.showPlayerOnePrompt();
          MYAPP.display.hidePlayerTwoPrompt();
          MYAPP.turn = 1;
        }
      }
    }
  },
  updateSquare: function(number, symbol) {
    MYAPP.currentBoard[number] = symbol;
  },
  checkWin: function(symbol) {
    var currentBoard = MYAPP.currentBoard;
    var wins = MYAPP.winCombos;
    var winningCombo = [];
    var winner = wins.some(function(combination) {
      var winning = true;
      for (var i = 0; i < combination.length; i++) {
        if (currentBoard[combination[i]] !== symbol) {
          winning = false;
        }
      }
      if (winning) {
        winningCombo = combination;
      }
      return winning;
    });
    return [winner, winningCombo];
  },
  showWinningCombination: function() {
    var symbol = MYAPP.turn === 1 ? MYAPP.playerOneSymbol : MYAPP.playerTwoSymbol;
    var combo = MYAPP.game.checkWin(symbol)[1];
    for (var i = 0; i < combo.length; i++) {
      var currentBox = '.' + combo[i]; 
   // Black box and rotating test for winning combo  
        $(currentBox).children('i').addClass('win').children('span').addClass('rotate');
     }
  },
  updateScore: function(turn) {
    turn === 1 ? MYAPP.playerOneScore += 1 : MYAPP.playerTwoScore += 1; 
    
    MYAPP.display.updateScore(turn);
    
  },
  reset: function() {
    MYAPP.initializeVars();
    
    MYAPP.timeOuts.push(
      setTimeout(function() {
        MYAPP.display.hideDrawMessage();
        MYAPP.display.hideLoseMessage();
        MYAPP.display.hideWinMessage();
        $('.boxes li').fadeOut();
      }, 5000),
      setTimeout(function(){
        MYAPP.display.resetSquares();
        $('.boxes li').fadeIn();
        MYAPP.numFilledIn = 0;
      }, 6000),
    //Make sure time for next timeout is long enough
    //to not cause problems after first game
      setTimeout(function() {
        MYAPP.gameInPlay = true;
        MYAPP.game.play();
      }, 6000)
      );
  },
  resetGame: function() {
    $('#myCanvas').css('opacity', '0');
    $('.hard-reset').fadeOut();
    $('.points-divider, .score-1, .score-2').fadeOut();
    MYAPP.playerOneScore = 0;
    MYAPP.playerTwoScore = 0;
    MYAPP.display.resetSquares();
    MYAPP.initializeVars();
    MYAPP.gameInPlay = false;
    MYAPP.playerOneSymbol = null;
    MYAPP.playerTwoSymbol = null;
    MYAPP.timeOuts.forEach(function(timer) {
      clearTimeout(timer);
    });
    $('.draw-message, .win-message, .lose-message').hide();
    MYAPP.display.hidePlayerOnePrompt();
    MYAPP.display.hidePlayerTwoPrompt();
    MYAPP.display.showGameChoice();
  }
};

/* End Game Logic */
  
/*================================
    Computer Move Decisions
=================================*/    

MYAPP.computer = {
  computerWhichMove: function () {
    var move = this.winOrBlockChoice('win')[0];
    if (!move) {
      move = this.winOrBlockChoice('block')[0];
      console.log(this.winOrBlockChoice('block'));
    }
    if (!move) {
      move = this.doubleThreatChoice('win');
    }
    if (!move) {
      move = this.doubleThreatChoice('block');
    }
    if (!move) {
      move = this.firstPlay();
    }
    if (!move) {
      move = this.playCenter();
    }
    if (!move) {
      move = this.emptyCorner();
    }
    if (!move) {
      move = this.emptySide();
    }
    move = (move && MYAPP.currentBoard[move]) === '' ? move : false;
    return move;
  },

  winOrBlockChoice: function(choiceType, board) {
    var board = board || MYAPP.currentBoard;
    if (choiceType === 'win') {
      var currentSymbol = MYAPP.playerTwoSymbol;
      var opponentSymbol = MYAPP.playerOneSymbol;
    } else if (choiceType === 'block') {
      var currentSymbol = MYAPP.playerOneSymbol;
      var opponentSymbol = MYAPP.playerTwoSymbol;
    } else {
      return;
    }
    var moves = [];
    MYAPP.winCombos.forEach(function(combo) {
      var notFound = [];
      var notPlayer = true;
      for (var i = 0; i < combo.length; i++) {
        if (board[combo[i]] !== currentSymbol) {
          if (board[combo[i]] === opponentSymbol) {
            notPlayer = false;
          } else {
            notFound.push(combo[i]);
          }
        }
      }
      if (notFound.length === 1 && notPlayer) {
        var move = notFound[0];
        moves.push(move);
      }
    });
    return moves;
},

  doubleThreatChoice: function(choiceType) {
  // use winChoice function to test a spot for double threat
  var board = MYAPP.currentBoard;
  var move;

  if (choiceType === 'win') {
    var currentSymbol = MYAPP.playerTwoSymbol;
    var opponentSymbol = MYAPP.playerOneSymbol;
  } else if (choiceType === 'block') {
    var currentSymbol = MYAPP.playerOneSymbol;
    var opponentSymbol = MYAPP.playerTwoSymbol;
  }

  // forced diagonal win on 4th move prevention
    if (board[5] === currentSymbol && MYAPP.numFilledIn === 3) {
      if ((board[1] === opponentSymbol && board[9] === opponentSymbol) || (board[3] === opponentSymbol && board[7] === opponentSymbol)) {
        // Play an edge to block double threat
        move = this.emptySide();
      }
    }
  
    if (!move && board[5] === opponentSymbol && MYAPP.numFilledIn === 2) {
      move = this.diagonalSecondAttack();
    }

  if (!move) {
    // clone current board;
    var testBoard = $.extend({}, board);
    for (var i = 1; i <= 9; i++) {

      testBoard = $.extend({}, board);
      if (testBoard[i] === '') {
        testBoard[i] = currentSymbol;
        if (this.winOrBlockChoice(choiceType, testBoard).length >= 2) {
          move = i;
        }
      }
    }
  }
  return move || false;
},

  diagonalSecondAttack: function() {
  var board = MYAPP.currentBoard;
  var comp = MYAPP.playerTwoSymbol;
  var corners = [1,3,7,9];
  for (var i = 0; i < corners.length; i++) {
    if (board[corners[i]] === comp) {
      return 10 - corners[i];
    }
  }
},

  firstPlay: function() {
  var board = MYAPP.currentBoard;
  var corners = [1, 3, 7, 9];
  var move;
  if (MYAPP.numFilledIn === 1) {
    // player plays center
    if (board[5] === MYAPP.playerOneSymbol) {
      var cornerNum = Math.floor(Math.random() * 4 + 1);
      move = [1, 3, 7, 9][cornerNum];
    }
    //player plays corner, play opposite corner
    else {
      for (var i = 0; i < corners.length; i++) {
        if (MYAPP.currentBoard[corners[i]] === MYAPP.playerOneSymbol) {
          move = 5;
        }
      }
    }
  } else if (MYAPP.numFilledIn === 0) {
    var cornerNum = Math.floor(Math.random() * corners.length + 1);
    move = corners[cornerNum];
  }
  return move ? move : false;
},
  
  playCenter: function() {
    if (MYAPP.currentBoard[5] === '') {
      return 5;
    }
  },
  emptyCorner: function() {
  var board = MYAPP.currentBoard;
  var corners = [1, 3, 7, 9];
  var move;
  for (var i = 0; i < corners.length; i++) {
    if (board[corners[i]] === '') {
      move = corners[i];
    }
  }
  return move || false;
},

  emptySide: function() {
  var sides = [2, 4, 6, 8];
  for (var i = 0; i < sides.length; i++) {
    if (MYAPP.currentBoard[sides[i]] === '') {
      return sides[i];
    }
  }
  return false;
}
}

/* End Computer Move Decisions */  

$(document).ready(function() {  
  MYAPP.initializeGame();
});

/* end game initialization */

Comments