问BS4是否更改下拉按钮值以匹配选定的下拉值？

EN

<div class="btn-group">
  <button class="btn btn-sm dropdown-toggle px-0 mr-3" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Sort by:
  </button>
  <div class="dropdown-menu">
    <a class="dropdown-item active" href="#">Most Recent</a>
    <a class="dropdown-item" href="#">Popular</a>
    <a class="dropdown-item" href="#">Trending</a>
    <a class="dropdown-item" href="#">Acending</a>
    <a class="dropdown-item" href="#">Decending</a>
  </div>
</div>

// Find all drop downs and check their classes.
$(".dropdown-menu a").click(function() {

  // Find the dropdown toggle and append the text.
  $(".dropdown-toggle:first-child").append($(this).text());

});