How can i add icon to bootstrap dropdown

Question

I have this code

        <div class="btn-group" dropdown>
            <button type="button" class="btn btn-danger">Action</button>
            <button type="button" class="btn btn-danger dropdown-toggle" dropdown-toggle>
                <span class="caret"></span>
                <span class="sr-only">Split button!</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>

which looks like

I want to add icon like cog insteaqd of Text like this

I have tried this

<button type="button" class="glyphicon glyphicon-cog"></button>

buts not working

Answer 1

For a button, the icon needs to go inside the button as the button's contents, so instead of <button type="button" class="glyphicon glyphicon-cog"></button> it should be

<button type="button" class="btn">
    <span class="glyphicon glyphicon-cog"></span>
</button>

Edit: to add the caret in Bootstrap, you use <span class="caret"></span>

So the end result to get a button with a cog and dropdown caret is:

<button type="button" class="btn">
    <span class="glyphicon glyphicon-cog"></span><span class="caret"></span>
</button>

When I paste that code into Bootstrap's homepage, I get this: