jquery bind
node2:/var/www/html/js#cat h12.html
<p>aaaa</p>
<a>bbbb</a>
<p>cccc</p>
<li>dddd</li>
<script type="text/javascript" src="jquery-2.2.2.min.js"></script>
<script type="text/javascript" src="h12.js"></script>
node2:/var/www/html/js#
node2:/var/www/html/js#cat h12.js
$("p").bind("click",function(){
alert("这个段落被点击了。");
});