<script type="text/javascript" src="/js/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("button").click(function(){
$("p").css("color",function(){
<p>This is a paragraph.</p>
<p>This is another paragraph.</p>
<button>设置所有 p 元素的 color 属性</button>