我发现了一个有趣又快捷的方法。 IE支持导航器。systemLanguage返回“en-US”，其他浏览器返回undefined。

<script>
    var lang = navigator.systemLanguage;
    if (lang!='en-US'){document.write("Well, this is not internet explorer");}
    else{document.write("This is internet explorer");}
</script>

下面的代码片段将显示如何显示UI元素取决于IE版本和浏览器

$(document).ready(function () {

var msiVersion = GetMSIieversion();
if ((msiVersion <= 8) && (msiVersion != false)) {

    //Show UI elements specific to IE version 8 or low

    } else {
    //Show UI elements specific to IE version greater than 8 and for other browser other than IE,,ie..Chrome,Mozila..etc
    }
}
);

下面的代码将给出我们如何获得IE版本

function GetMSIieversion() {

var ua = window.navigator.userAgent;
var msie = ua.indexOf('MSIE ');
if (msie > 0) {
    // IE 10 or older => return version number
    return parseInt(ua.substring(msie + 5, ua.indexOf('.', msie)), 10);
}

var trident = ua.indexOf('Trident/');
if (trident > 0) {
    // IE 11 => return version number
    var rv = ua.indexOf('rv:');
    return parseInt(ua.substring(rv + 3, ua.indexOf('.', rv)), 10);
}

var edge = ua.indexOf('Edge/');
if (edge > 0) {
    // Edge (IE 12+) => return version number
    return parseInt(ua.substring(edge + 5, ua.indexOf('.', edge)), 10);
}

// other browser like Chrome,Mozila..etc
return false;

}

var browser = navigator.appName;
var version = navigator.appVersion;

然而，请注意，两者并不一定反映事实。许多浏览器都可以设置为其他浏览器的掩码。例如，你不能总是确定用户是用IE6还是用伪装成IE6的Opera上网。

下面是我如何为Internet Explorer做自定义CSS:

在我的JavaScript文件:

function isIE () {
      var myNav = navigator.userAgent.toLowerCase();
      return (myNav.indexOf('msie') != -1) ? parseInt(myNav.split('msie')[1]) : false;
}

jQuery(document).ready(function(){
    if(var_isIE){
            if(var_isIE == 10){
                jQuery("html").addClass("ie10");
            }
            if(var_isIE == 8){
                jQuery("html").addClass("ie8");
                // you can also call here some function to disable things that 
                //are not supported in IE, or override browser default styles.
            }
        }
    });

然后在我的CSS文件中，定义每个不同的样式:

.ie10 .some-class span{
    .......
}
.ie8 .some-class span{
    .......
}

这是我正在使用的:

var ua = navigator.userAgent;
var info = {
        browser: /Edge\/\d+/.test(ua) ? 'ed' : /MSIE 9/.test(ua) ? 'ie9' : /MSIE 10/.test(ua) ? 'ie10' : /MSIE 11/.test(ua) ? 'ie11' : /MSIE\s\d/.test(ua) ? 'ie?' : /rv\:11/.test(ua) ? 'ie11' : /Firefox\W\d/.test(ua) ? 'ff' : /Chrom(e|ium)\W\d|CriOS\W\d/.test(ua) ? 'gc' : /\bSafari\W\d/.test(ua) ? 'sa' : /\bOpera\W\d/.test(ua) ? 'op' : /\bOPR\W\d/i.test(ua) ? 'op' : typeof MSPointerEvent !== 'undefined' ? 'ie?' : '',
        os: /Windows NT 10/.test(ua) ? "win10" : /Windows NT 6\.0/.test(ua) ? "winvista" : /Windows NT 6\.1/.test(ua) ? "win7" : /Windows NT 6\.\d/.test(ua) ? "win8" : /Windows NT 5\.1/.test(ua) ? "winxp" : /Windows NT [1-5]\./.test(ua) ? "winnt" : /Mac/.test(ua) ? "mac" : /Linux/.test(ua) ? "linux" : /X11/.test(ua) ? "nix" : "",
        touch: 'ontouchstart' in document.documentElement,
        mobile: /IEMobile|Windows Phone|Lumia/i.test(ua) ? 'w' : /iPhone|iP[oa]d/.test(ua) ? 'i' : /Android/.test(ua) ? 'a' : /BlackBerry|PlayBook|BB10/.test(ua) ? 'b' : /Mobile Safari/.test(ua) ? 's' : /webOS|Mobile|Tablet|Opera Mini|\bCrMo\/|Opera Mobi/i.test(ua) ? 1 : 0,
        tablet: /Tablet|iPad/i.test(ua),
};

信息属性:

browser: gc for Google Chrome; ie9-ie11 for IE; ie? for old or unknown IE; ed for Edge; ff for Firefox; sa for Safari; op for Opera. os: mac win7 win8 win10 winnt winxp winvista linux nix mobile: a for Android; i for iOS (iPhone iPad); w for Windows Phone; b for Blackberry; s for undetected mobile running Safari; 1 for other undetected mobile; 0 for non-mobile touch: true for touch enabled devices, including touch laptops/notebooks that has both mouse and touch together; false for no touch support tablet: true or false

https://jsfiddle.net/oriadam/ncb4n882/

 var isOpera = !!window.opera || navigator.userAgent.indexOf('Opera') >= 0;
        // Opera 8.0+ (UA detection to detect Blink/v8-powered Opera)
        var isFirefox = typeof InstallTrigger !== 'undefined';   // Firefox 1.0+
        var isSafari = Object.prototype.toString.call(window.HTMLElement).indexOf('Constructor') > 0;
        // At least Safari 3+: "[object HTMLElementConstructor]"
        var isChrome = !!window.chrome;                          // Chrome 1+
        var isIE = /*@cc_on!@*/false; 

你可以阅读更多 如何检测Safari, Chrome, IE, Firefox和Opera浏览器?