W3School TIY
编辑您的代码：
<html> <head> <script type="text/javascript" src="../jquery/jquery.js"></script> <script type="text/javascript"> $(document).ready(function(){ $(".btn1").click(function(){ alert($("p").html()); }); }); </script> </head> <body> <p>This is a paragraph.</p> <button class="btn1">改变 p 元素的内容</button> </body> </html>
查看结果: