javascript - 将行插入到表的开头

Question

我正在尝试在许多表的开头插入一行

$('table > tbody > tr:first').before('<tr><td>Stuff</td></tr>');

仅向第一个表和

添加新的 tr

$("tbody").each(function() {
      $('table > tbody > tr:first').before('<tr><td>Stuff</td></tr>');
    });

正在将所有新的tr再次添加到第一个表中。我该如何解决这个问题？

$("tbody").each(function() {
  $('table > tbody > tr:first').before('<tr><td>Stuff</td></tr>');
});

$('table > tbody > tr:first').before('<tr><td>Stuff</td></tr>');

table,
th,
td {
  border: 1px solid #eee;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table>
  <tbody>
    <tr>
      <td>January</td>
      <td>$100</td>
    </tr>
    <tr>
      <td>February</td>
      <td>$80</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>January</td>
      <td>$100</td>
    </tr>
    <tr>
      <td>February</td>
      <td>$80</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>January</td>
      <td>$100</td>
    </tr>
    <tr>
      <td>February</td>
      <td>$80</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>January</td>
      <td>$100</td>
    </tr>
    <tr>
      <td>February</td>
      <td>$80</td>
    </tr>
  </tbody>
</table>

Answer 1

使用$(this)给每个表提供引用。

$("tbody ").each(function() {
  $(this).before('<tr><td>Stuff</td></tr>');
});

table,
th,
td {
  border: 1px solid #eee;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table>
  <tbody>
    <tr>
      <td>January</td>
      <td>$100</td>
    </tr>
    <tr>
      <td>February</td>
      <td>$80</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>January</td>
      <td>$100</td>
    </tr>
    <tr>
      <td>February</td>
      <td>$80</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>January</td>
      <td>$100</td>
    </tr>
    <tr>
      <td>February</td>
      <td>$80</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>January</td>
      <td>$100</td>
    </tr>
    <tr>
      <td>February</td>
      <td>$80</td>
    </tr>
  </tbody>
</table>

P.S - 如果你想要它在里面 tbody你可以使用$(this).find("tr:first").before('<tr><td>Stuff</td></tr>');来做到这一点