正则，js函数math()提取混乱字符串中多个字符串内容

var a='start111111endstart222222endasdfasdfasdfakjsfhaksdf'+
'start333333endstart444444end66666666666sdfghsdfgsdg'
alert(a.match(/start.*?end/img).join("=").replace(/start/g,"").replace(/end/g,"").split("="))