我写这个是为了满足我的需要。

它可以获取信息，比如是否是移动设备或是否有视网膜显示器

试一试

var nav = {
        isMobile:function(){
            return (navigator.userAgent.match(/iPhone|iPad|iPod|Android|BlackBerry|Opera Mini|IEMobile/i) != null);
        },
        isDesktop:function(){
            return (navigator.userAgent.match(/iPhone|iPad|iPod|Android|BlackBerry|Opera Mini|IEMobile/i) == null);
        },
        isAndroid: function() {
            return navigator.userAgent.match(/Android/i);
        },
        isBlackBerry: function() {
            return navigator.userAgent.match(/BlackBerry/i);
        },
        isIOS: function() {
            return navigator.userAgent.match(/iPhone|iPad|iPod/i);
        },
        isOpera: function() {
            return navigator.userAgent.match(/Opera Mini/i);
        },
        isWindows: function() {
            return navigator.userAgent.match(/IEMobile/i);
        },
        isRetina:function(){
            return window.devicePixelRatio && window.devicePixelRatio > 1;
        },
        isIPad:function(){
            isIPad = (/ipad/gi).test(navigator.platform);
            return isIPad;
        },
        isLandscape:function(){
            if(window.innerHeight < window.innerWidth){
                return true;
            }
            return false;
        },
        getIOSVersion:function(){
            if(this.isIOS()){
                var OSVersion = navigator.appVersion.match(/OS (\d+_\d+)/i);
                OSVersion = OSVersion[1] ? +OSVersion[1].replace('_', '.') : 0;
                return OSVersion;
            }
            else
                return false;
        },
        isStandAlone:function(){
            if(_.is(navigator.standalone))
                return navigator.standalone;
            return false;
        },
        isChrome:function(){
            var isChrome = (/Chrome/gi).test(navigator.appVersion);
            var isSafari = (/Safari/gi).test(navigator.appVersion)
            return isChrome && isSafari;
        },
        isSafari:function(){
            var isSafari = (/Safari/gi).test(navigator.appVersion)
            var isChrome = (/Chrome/gi).test(navigator.appVersion)
            return !isChrome && isSafari;
        }
}

您可以看到浏览器显示的内容，并使用该信息记录或测试多个浏览器。

navigator.sayswho= (function(){ var ua= navigator.userAgent; var tem; var M= ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || []; if(/trident/i.test(M[1])){ tem= /\brv[ :]+(\d+)/g.exec(ua) || []; return 'IE '+(tem[1] || ''); } if(M[1]=== 'Chrome'){ tem= ua.match(/\b(OPR|Edge)\/(\d+)/); if(tem!= null) return tem.slice(1).join(' ').replace('OPR', 'Opera'); } M= M[2]? [M[1], M[2]]: [navigator.appName, navigator.appVersion, '-?']; if((tem= ua.match(/version\/(\d+)/i))!= null) M.splice(1, 1, tem[1]); return M.join(' '); })(); console.log(navigator.sayswho); // outputs: `Chrome 62`

使用这个:http://www.quirksmode.org/js/detect.html

alert(BrowserDetect.browser); // will say "Firefox"
alert(BrowserDetect.version); // will say "3" or "4"

这让我有了火狐的版本，

    let versionNumber = parseInt(window.navigator.userAgent.match(/Firefox\/([0- 
    9]+)\./)[1]);

加上我自己对赫尔曼答案的实现。我需要操作系统检测，所以它被添加。还包括一些ES6代码(因为我们有一个转译器)，你可能需要es5化。

detectClient() {
    let nav = navigator.appVersion,
        os = 'unknown',
        client = (() => {
            let agent = navigator.userAgent,
                engine = agent.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [],
                build;

            if(/trident/i.test(engine[1])){
                build = /\brv[ :]+(\d+)/g.exec(agent) || [];
                return {browser:'IE', version:(build[1] || '')};
            }

            if(engine[1] === 'Chrome'){
                build = agent.match(/\bOPR\/(\d+)/);

                if(build !== null) {
                    return {browser: 'Opera', version: build[1]};
                }
            }

            engine = engine[2] ? [engine[1], engine[2]] : [navigator.appName, nav, '-?'];

            if((build = agent.match(/version\/(\d+)/i)) !== null) {
                engine.splice(1, 1, build[1]);
            }

            return {
              browser: engine[0],
              version: engine[1]
            };
        })();

    switch (true) {
        case nav.indexOf('Win') > -1:
            os = 'Windows';
        break;
        case nav.indexOf('Mac') > -1:
            os = 'MacOS';
        break;
        case nav.indexOf('X11') > -1:
            os = 'UNIX';
        break;
        case nav.indexOf('Linux') > -1:
            os = 'Linux';
        break;
    }        

    client.os = os;
    return client;
}

返回:对象{浏览器:"Chrome"，版本:"50"，操作系统:"UNIX"}

navigator.sayswho= (function(){ var ua= navigator.userAgent, tem, M= ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || []; if(/trident/i.test(M[1])){ tem= /\brv[ :]+(\d+)/g.exec(ua) || []; return 'IE '+(tem[1] || ''); } if(M[1]=== 'Chrome'){ tem= ua.match(/\b(OPR|Edge)\/(\d+)/); if(tem!= null) return tem.slice(1).join(' ').replace('OPR', 'Opera'); } M= M[2]? [M[1], M[2]]: [navigator.appName, navigator.appVersion, '-?']; if((tem= ua.match(/version\/(\d+)/i))!= null) M.splice(1, 1, tem[1]); return M.join(' '); })(); console.log(navigator.sayswho); // outputs: `Chrome 62`