我是新手.我正在尝试Bootstrap-select,但我没有像这里得到所需的效果https://developer.snapappointments.com/bootstrap-select/.我已下载文件并指向头部的CSS和JS.我已经在头部启用了Bootstrap-select,但仍然无法工作 - 我只是获得默认外观.这是我的完整代码.我在这做错了什么？任何提示将不胜感激.
<html>
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<title>Untitled 1</title>
<link href="bootstrap-master/docs/assets/css/bootstrap.css" rel="stylesheet" />
<link href="bootstrap-master/docs/assets/css/bootstrap-select.css" rel="stylesheet" />
<script src="bootstrap-master/docs/assets/js/bootstrap-select.js" type="text/javascript"></script>
<script>
$('.selectpicker').selectpicker({
style: 'btn-info',
size: 4
});
</script>
</head>
<body>
<select class="selectpicker">
<option>Mustard</option>
<option>Ketchup</option>
<option>Relish</option>
</select>
</body>
</html>