这结合了kennebec的(K)答案和Hermann Ingjaldsson的(H)答案:

维护原始答案的最小代码。(K) 使用Microsoft Edge (K) 扩展导航器对象，而不是创建新的变量/对象。(K) 将浏览器版本和名称分离为独立的子对象。(H)

navigator.browserSpecs = (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 {name:'IE',version:(tem[1] || '')}; } if(M[1]=== 'Chrome'){ tem = ua.match(/\b(OPR|Edge)\/(\d+)/); if(tem != null) return {name:tem[1].replace('OPR', 'Opera'),version:tem[2]}; } 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 {name:M[0], version:M[1]}; })(); console.log(navigator.browserSpecs); //Object { name: "Firefox", version: "42" } if (navigator.browserSpecs.name == 'Firefox') { // Do something for Firefox. if (navigator.browserSpecs.version > 42) { // Do something for Firefox versions greater than 42. } } else { // Do something for all other browsers. }

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`

浏览器JavaScript库提供了此功能。

if (bowser.msie && bowser.version <= 6) {
  alert('Hello China');
}

它似乎保养得很好。

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"}

这让我有了火狐的版本，

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

这结合了kennebec的(K)答案和Hermann Ingjaldsson的(H)答案:

维护原始答案的最小代码。(K) 使用Microsoft Edge (K) 扩展导航器对象，而不是创建新的变量/对象。(K) 将浏览器版本和名称分离为独立的子对象。(H)

navigator.browserSpecs = (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 {name:'IE',version:(tem[1] || '')}; } if(M[1]=== 'Chrome'){ tem = ua.match(/\b(OPR|Edge)\/(\d+)/); if(tem != null) return {name:tem[1].replace('OPR', 'Opera'),version:tem[2]}; } 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 {name:M[0], version:M[1]}; })(); console.log(navigator.browserSpecs); //Object { name: "Firefox", version: "42" } if (navigator.browserSpecs.name == 'Firefox') { // Do something for Firefox. if (navigator.browserSpecs.version > 42) { // Do something for Firefox versions greater than 42. } } else { // Do something for all other browsers. }