51help TIY
码：
<!DOCTYPE html> <html> <head> <script src="../../ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js" tppabs="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script> <script> $(document).ready(function(){ $("button").click(function(){ $("h1,h2,p").addClass("blue"); $("div").addClass("important"); }); }); </script> <style type="text/css"> .important { font-weight:bold; font-size:xx-large; } .blue { color:blue; } </style> </head> <body> <h1>标题 1</h1> <h2>标题 2</h2> <p>落。</p> <p>段落。</p> <div></div> <br> <button>类</button> </body> </html>
查看结果: