判断是否是ie浏览器

//判断是否是IE浏览器，包括Edge浏览器
function IEVersion()
{
    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; WOW64; Trident/7.0;") > -1 && !isIE; //判断是否IE的Edge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
    }
    else if(isEdge)
    {
        return "Edge";
    }
    else
    {
        return "-1";//非IE
    }
}