<!DOCTYPE html><html><head><meta charset="utf-8"><script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script><script>$(document).ready(function(){ $("button").click(function(){ $("h1,h2,p").toggleClass("blue"); });});</script><style type="text/css">.blue{color:blue;}</style></head><body><h1 class="blue">标题 1</h1><h2 class="blue">标题 2</h2><p class="blue">这是一个段落。</p><p>这是另外一个段落。</p><br><button>切换 class</button></body></html>联系客服
