小旋风SEO教程 TIY
编辑您的代码：
<html><head><script type="text/javascript" src="/w3c/jquery/jquery.js"></script><script type="text/javascript"> $(document).ready(function(){ $("button").click(function(){ $("p:first").removeClass("intro").addClass('main'); }); }); </script><style type="text/css"> .intro { font-size:120%; color:red; } .main { font-size:90%; color:blue; } </style><link rel="canonical" href="https://www.xxfseo.com/w3c/tiy/t.asp-f=jquery_attributes_addremoveclass.html" /></head><body><h1>This is a heading</h1><p class="bd1153 intro">This is a paragraph.</p><p>This is another paragraph.</p><button>改变第一个段落的类</button></body></html>
查看结果: