区分IE版本的js代码

 1 function IEVersion() {
 2         var userAgent = navigator.userAgent; //取得浏览器的userAgent字符串  
 3         var isIE = userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1; //判断是否IE<11浏览器  
 4         var isEdge = userAgent.indexOf("Edge") > -1 && !isIE; //判断是否IE的Edge浏览器  
 5         var isIE11 = userAgent.indexOf('Trident') > -1 && userAgent.indexOf("rv:11.0") > -1;
 6         if(isIE) {
 7             var reIE = new RegExp("MSIE (\\d+\\.\\d+);");
 8             reIE.test(userAgent);
 9             var fIEVersion = parseFloat(RegExp["$1"]);
10             if(fIEVersion == 7) {
11                 return 7;
12             } else if(fIEVersion == 8) {
13                 return 8;
14             } else if(fIEVersion == 9) {
15                 return 9;
16             } else if(fIEVersion == 10) {
17                 return 10;
18             } else {
19                 return 6;//IE版本<=7
20             }   
21         } else if(isEdge) {
22             return 'edge';//edge
23         } else if(isIE11) {
24             return 11; //IE11  
25         }else{
26             return -1;//不是ie浏览器
27         }
28     }