The following code shows how to test Button Variants.
<!-- w ww. j av a 2s. c o m-->
<!DOCTYPE html>
<html lang="en">
<head>
<link rel="stylesheet"
href="https://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<link rel="stylesheet"
href="https://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap-theme.min.css">
<script
src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script
src="https://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
</head>
<body style='margin:30px'>
<div class="container">
<button type="button" class="btn btn-primary btn-lg">Large button</button>
<button type="button" class="btn btn-primary">Default button</button>
<button type="button" class="btn btn-primary btn-sm">Small button</button>
<button type="button" class="btn btn-primary btn-xs">Extra small button</button>
</div>
</body>
</html>