title: Bootstrap 4 Dropdown Menu not working?
body: <p>I copied the official Bootstrap 4 example for dropdown menus but it is not working, that is nothing is dropped down.</p>
  
  <pre><code>&lt;li class="nav-item dropdown"&gt;
      &lt;a class="nav-link dropdown-toggle" href="#" id="dropdown01" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"&gt;Dropdown&lt;/a&gt;
      &lt;div class="dropdown-menu" aria-labelledby="dropdown01"&gt;
      &lt;a class="dropdown-item" href="#"&gt;Action&lt;/a&gt;
      &lt;a class="dropdown-item" href="#"&gt;Another action&lt;/a&gt;
      &lt;a class="dropdown-item" href="#"&gt;Something else here&lt;/a&gt;
    &lt;/div&gt;
  &lt;/li&gt;
  </code></pre>