IE
IE11
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko
if(str.indexOf("rv:11") > -1)//判断IE11
//...
IE10
User-Agent: Mozilla/5.0(compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)
if(str.indexOf("MSIE 10.0")>-1)//判断IE10
// ...
IE9
User-Agent: Mozilla/5.0(compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)
if(str.indexOf("MSIE 9.0") >-1)//判断IE9
//....
IE8
User-Agent: Mozilla/4.0(compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0)
if(str.indexOf("MSIE 8.0") >-1)//判断IE8
//....
Chrome
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36
if(str.indexOf("Chrome") >-1)//判断Chrome
//...