login glyphicon bootstrap 4 code example
Example 1: glyphicon cdn bootstrap 4
<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" type="text/css" rel="stylesheet">
Example 2: heart button bootstrap
<button type="button" class="btn btn-default" aria-label="Left Align">
<span class="glyphicon glyphicon-align-left" aria-hidden="true"></span>
</button>
<button type="button" class="btn btn-default btn-lg">
<span class="glyphicon glyphicon-star" aria-hidden="true"></span> Star
</button>