外部的jQuery连接,引入便可使用javascript
百度:java
<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
google:jquery
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
cdn加速:ajax
<script src="https://cdn.bootcdn.net/ajax/libs/jquery/2.2.0/jquery.js" type="text/javascript" charset="utf-8"></script>