javascript - 在 jQuery 中按类名对 Dom 元素进行计数

Question

我需要帮助按类名和数据日期获取元素计数:

<td data-date="2017-11-10">
    <div class="animal">Mouse</div>
    <div class="animal">Dog</div>
</td>
<td data-date="2017-11-11">
    <div class="animal">Bird</div>
</td>
<td data-date="2017-11-12">
    <div class="animal">Cat</div>
    <div class="animal">Horse</div>
    <div class="animal">Snake</div>
    <div class="animal">Tiger</div>
</td>

输出

2017-11-10: 2
2017-11-11: 1
2017-11-12: 4

谢谢。

Answer 1

1. 循环每个 tr td。
2. 使用.attr()获取属性
3. 使用.length获取类的元素数量

$('table tr td[data-date]').each(function() {
  var $this = $(this);



  console.log($this.attr('data-date') + " : " +
    $this.find('.animal').length)
})

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table>
  <tr>
  <td>Not included td</td>
    <td data-date="2017-11-10">
      <div class="animal">Mouse</div>
      <div class="animal">Dog</div>
    </td>
    <td data-date="2017-11-11">
      <div class="animal">Bird</div>
    </td>
    <td data-date="2017-11-12">
      <div class="animal">Cat</div>
      <div class="animal">Horse</div>
      <div class="animal">Snake</div>
      <div class="animal">Tiger</div>
    </td>
     <td>Not included td</td>
  </tr>
</table>