该引导按钮下拉菜单不起作用。 但为什么？

Question

At first I was using regular html but the dropdown button wasn't working so I changed to jsfiddle to test it out. I saw that the dropwdown still didn't work.

Here's the jsfiddle: https://jsfiddle.net/ugpqxpn6/2/

<div>

<!-- Single button -->
<div class="btn-group">
  <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Action <span class="caret"></span>
  </button>
  <ul class="dropdown-menu">
    <li><a href="#">Action</a></li>
    <li><a href="#">Another action</a></li>
    <li><a href="#">Something else here</a></li>
    <li role="separator" class="divider"></li>
    <li><a href="#">Separated link</a></li>
  </ul>
</div>

</div>

I don't understand why it wouldn't work. I took a look at some similar questions and saw that maybe not including jquery was my problem so I added it but it still seems to malfunction. Can anybody help?

Answer 1

Hit F12 on your keyboard to see the developer console, you have a Javascript error:

Error: Bootstrap's JavaScript requires jQuery

Make sure you're including jQuery before bootstrap's js files.

Answer 2

Here is a working fiddle with bootstrap.min.js and jquery.min

https://jsfiddle.net/nrgxh5rr/

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>