$(function () { var url = "bin/SKYNET_Image/20130618/NORMAL/00000001/000003_1371550206_0001.jpg"; alert(url.substr(url.indexOf('.')-1, 1)); });
if(str.indexOf(".")!=-1){ str.substring(0,str.indexOf(".")); return str;}传你的字符串进去,返回回来的就是'.'之前的字符串
