如何通过jQuery在<table>中向上或向下移动<tr>？

$(document).ready(function() {
  // 向上移动
  $('.move-up').click(function() {
    var currentRow = $(this).closest('tr');
    currentRow.prev().before(currentRow);
  });

  // 向下移动
  $('.move-down').click(function() {
    var currentRow = $(this).closest('tr');
    currentRow.next().after(currentRow);
  });
});

  <tr class="moveable-row">
    <td>行1</td>
    <td><button class="move-up">向上移动</button></td>
    <td><button class="move-down">向下移动</button></td>
  </tr>
  <tr class="moveable-row">
    <td>行2</td>
    <td><button class="move-up">向上移动</button></td>
    <td><button class="move-down">向下移动</button></td>
  </tr>
  <tr class="moveable-row">
    <td>行3</td>
    <td><button class="move-up">向上移动</button></td>
    <td><button class="move-down">向下移动</button></td>
  </tr>
</table>