<!DOCTYPE html> <html> <head> <style> div { width:60px; height:60px; margin:10px; float:left; border:2px solid blue; } .blue { background:blue; } </style> <script type="text/javascript" src="/jquery/jquery.js"></script> </head> <body> <div></div> <div></div> <div></div> <div></div> <div></div> <div></div> <script>$("body").find("div").eq(1).addClass("blue");</script> </body> </html>
$(document).ready(function(){ $("p:eq(1)").css("background-color","#B2E0FF"); });
$(".ky-crsos-menubar li:eq(0)").addClass("hit");
原文：http://www.cnblogs.com/flytogalaxy/p/7514519.html