<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="//cdn.bootcss.com/bootstrap/3.3.6/css/bootstrap.min.css">
<script src="//cdn.bootcss.com/jquery/2.1.1/jquery.min.js"></script>
<script src="//cdn.bootcss.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<h2>实例</h2>
<p> .show 类强制一个元素显示:</p>
<p class="show">该段落强制显示</p>
<p> .hidden 类强制一个元素隐藏 :</p>
<p class="hidden">该段落强制隐藏</p>
</div>
</body>
</html>