Button Dropdowns
Use any button to trigger a dropdown menu by placing it within a .btn-group and providing the proper menu markup.
Plugin dependency
Button dropdowns require the dropdown plugin to be included in your version of Bootstrap.
Single button dropdowns
Turn a button into a dropdown toggle with some basic markup changes.
<!-- Single button -->
<div class="btn-group">
<button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">
Action <span class="caret"></span>
</button>
<ul class="dropdown-menu" role="menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li class="divider"></li>
<li><a href="#">Separated link</a></li>
</ul>
</div>
Dropup variation
Trigger dropdown menus above elements by adding .dropup to the parent.
<div class="btn-group dropup">
<button type="button" class="btn btn-default">Dropup</button>
<button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">
<span class="caret"></span>
<span class="sr-only">Toggle Dropdown</span>
</button>
<!-- Dropdown menu links -->
<ul class="dropdown-menu">
</ul>
</div>