javascript - 卡牌游戏拖放

Question

Can someone play this game and explain to me why the .correct.length class in line 102 is equal to 1?. I put an alert box on it to confirm the length. Here is a working fiddle http://jsfiddle.net/6haMV/141/

$(init);

function init() {

  $('#element_1').data('number', 1).attr('id', 'card' + 1).draggable({
    containment: '#content',
    stack: '#cardPile div',
    cursor: 'pointer',
    revert: true

  });

  $('#element_2').data('number', 2).attr('id', 'card' + 2).draggable({
    containment: '#content',
    stack: '#cardPile div',
    cursor: 'pointer',
    revert: true
  });

  $('#element_3').data('number', 3).attr('id', 'card' + 3).draggable({
    containment: '#content',
    stack: '#cardPile div',
    cursor: 'pointer',
    revert: true
  });

  $('#element_4').data('number', 4).attr('id', 'card' + 4).draggable({
    containment: '#content',
    stack: '#cardPile div',
    cursor: 'pointer',
    revert: true
  });

  $('#element_5').data('number', 5).attr('id', 'card' + 5).draggable({
    containment: '#content',
    stack: '#cardPile div',
    cursor: 'pointer',
    revert: true
  });

  $('#element_6').data('number', 6).attr('id', 'card' + 6).draggable({
    containment: '#content',
    stack: '#cardPile div',
    cursor: 'pointer',
    revert: true
  });


  $('#slot_1').data('number', 1).droppable({
    accept: '#cardPile div',
    hoverClass: 'hovered',
    drop: handleCardDrop

  });

  $('#slot_2').data('number', 2).droppable({
    accept: '#cardPile div',
    hoverClass: 'hovered',
    drop: handleCardDrop
  });

  $('#slot_3').data('number', 3).droppable({
    accept: '#cardPile div',
    hoverClass: 'hovered',
    drop: handleCardDrop
  });

  $('#slot_4').data('number', 4).droppable({
    accept: '#cardPile div',
    hoverClass: 'hovered',
    drop: handleCardDrop
  });

  $('#slot_5').data('number', 5).droppable({
    accept: '#cardPile div',
    hoverClass: 'hovered',
    drop: handleCardDrop
  });

  $('#slot_6').data('number', 6).droppable({
    accept: '#cardPile div',
    hoverClass: 'hovered',
    drop: handleCardDrop
  });

}

var totalCards = $('#cardPile').children().length;
var totalMatches = 0;

function handleCardDrop(event, ui) {
  var slotNumber = $(this).data('number');
  var cardNumber = ui.draggable.data('number');

  if (slotNumber == cardNumber) {
    totalMatches++;
    ui.draggable.addClass('correct');
    ui.draggable.draggable('disable');
    alert("the .correct length is " + $(".correct").length);
    $(this).droppable('disable');
    ui.draggable.position({
      of: $(this),
      my: 'left top',
      at: 'left top'
    });
    ui.draggable.draggable('option', 'revert', false);
  }

  if (totalMatches == totalCards) {
    $('#basicModal').modal('show');
  }
}

@charset"utf-8";

/* CSS Document */

body {
  margin: 30px;
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.8em;
  color: #333;
}
#content {
  margin: 80px 70px;
  text-align: center;
  -moz-user-select: none;
  -webkit-user-select: none;
  user-select: none;
}
/* Header/footer boxes */

.wideBox {
  clear: both;
  text-align: center;
  margin: 70px;
  padding: 10px;
  background: #ebedf2;
  border: 1px solid #333;
}
.wideBox h1 {
  font-weight: bold;
  margin: 20px;
  color: #666;
  font-size: 1.5em;
}
#cardSlots {
  margin: 50px auto 0 auto;
}
#cardPile {
  margin: 0 auto;
}
#cardPile {
  width: 1200px;
  height: 120px;
  padding: 20px;
}
#cardSlots {
  width: 1200px;
  height: 1000px;
  padding: 20px;
  font-family: Arial, Helvetica, sans-serif;
  line-height: normal;
}
#cardSlots div,
#cardPile div {
  float: left;
  width: 80px;
  height: 50px;
  padding: 10px;
  padding-bottom: 0;
  border: 1px solid #333;
  -moz-border-radius: 10px;
  -webkit-border-radius: 10px;
  border-radius: 10px;
  margin: 0 0 0 10px;
  background: #fff;
}
#cardSlots div:first-child,
#cardPile div:first-child {
  margin-left: 0;
}
#cardSlots div.hovered {
  background: #aaa;
}
#cardSlots div {
  border: 1px dashed #333;
}
#cardPile div {
  background: #fff;
  border: 1px solid #005575;
  color: #000;
  font-size: 11px;
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.3;
}
#cardPile div.ui-draggable-dragging {
  -moz-box-shadow: 0 0 .5em rgba(0, 0, 0, .8);
  -webkit-box-shadow: 0 0 .5em rgba(0, 0, 0, .8);
  box-shadow: 0 0 .5em rgba(0, 0, 0, .8);
}
#card1.correct {
  background: #5fcf80;
  color: #fff;
}

<script src="http://netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>
<link href="http://netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css" rel="stylesheet" />
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.10.4/jquery-ui.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<div id="content" class="content">
  <!-- Modal -->

  <div id="cardPile">
    <div id="element_1">Card 1</div>
    <div id="element_2">Card 2</div>
    <div id="element_3">Card 3</div>
  </div>
  <div id="cardSlots">
    <div id="slot_1"></div>
    <div id="slot_2"></div>
    <div id="slot_3"></div>
  </div>
</div>


<!--Modal-->
<div class="modal fade" id="textModal">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
        <h4 class="modal-title" style="text-align:center">Great Work!</h4>

      </div>
      <div class="modal-body">Everything was matched :)</div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <a href="www.google.com">
          <button type="button" class="btn btn-primary">Next</button>
        </a>

      </div>
    </div>
  </div>
</div>

Answer 1

代码 $(". Correct").length 告诉 DOM 上具有类选择器 . Correct 的元素的数量。当你放下一个盒子时，该类就会出现在一个元素上，当你放下 2 个盒子时，元素数量就会增加到 2 个，依此类推......