判断当前浏览器类型

//判断当前浏览类型  
  function BrowserType()  
  {  
      var userAgent = navigator.userAgent; //取得浏览器的userAgent字符串  
      var isOpera = userAgent.indexOf("Opera") > -1; //判断是否Opera浏览器  
      var isIE = userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1 && !isOpera; //判断是否IE浏览器  
      var isEdge = userAgent.indexOf("Windows NT 6.1; Trident/7.0;") > -1 && !isIE; //判断是否IE的Edge浏览器  
      var isFF = userAgent.indexOf("Firefox") > -1; //判断是否Firefox浏览器  
      var isSafari = userAgent.indexOf("Safari") > -1 && userAgent.indexOf("Chrome") == -1; //判断是否Safari浏览器  
      var isChrome = userAgent.indexOf("Chrome") > -1 && userAgent.indexOf("Safari") > -1; //判断Chrome浏览器  
  
      if (isIE)   
      {  
           var reIE = new RegExp("MSIE (\d+\.\d+);");  
           reIE.test(userAgent);  
           var fIEVersion = parseFloat(RegExp["$1"]);  
           if(fIEVersion == 7)  
           { return "IE7";}  
           else if(fIEVersion == 8)  
           { return "IE8";}  
           else if(fIEVersion == 9)  
           { return "IE9";}  
           else if(fIEVersion == 10)  
           { return "IE10";}  
           else if(fIEVersion == 11)  
           { return "IE11";}  
           else  
           { return "0"}//IE版本过低  
       }//isIE end  
         
       if (isFF) {  return "FF";}  
       if (isOpera) {  return "Opera";}  
       if (isSafari) {  return "Safari";}  
       if (isChrome) { return "Chrome";}  
       if (isEdge) { return "Edge";}  
   }