浏览器嗅探

 var nVer = navigator.appVersion,
            nAgt = navigator.userAgent,
            browser = navigator.appName,
            version = '' + parseFloat(navigator.appVersion),
            majorVersion, nameOffset, verOffset, ix, network = 'unknown';
    // Opera
    if ((verOffset = nAgt.indexOf('Opera')) != -1) {
        browser = 'Opera';
        version = nAgt.substring(verOffset + 6);
        if ((verOffset = nAgt.indexOf('Version')) != -1) {
            version = nAgt.substring(verOffset + 8);
        }
    }
    // Opera Next
    if ((verOffset = nAgt.indexOf('OPR')) != -1) {
        browser = 'Opera';
        version = nAgt.substring(verOffset + 4);
    }
// MSIE
    else if ((verOffset = nAgt.indexOf('MSIE')) != -1) {
        browser = 'Microsoft Internet Explorer';
        version = nAgt.substring(verOffset + 5);
    }
// Chrome
    else if ((verOffset = nAgt.indexOf('Chrome')) != -1) {
        browser = 'Chrome';
        version = nAgt.substring(verOffset + 7);
    }
// Safari
    else if ((verOffset = nAgt.indexOf('Safari')) != -1) {
        browser = 'Safari';
        version = nAgt.substring(verOffset + 7);
        if ((verOffset = nAgt.indexOf('Version')) != -1) {
            version = nAgt.substring(verOffset + 8);
        }
    }
// Firefox
    else if ((verOffset = nAgt.indexOf('Firefox')) != -1) {
        browser = 'Firefox';
        version = nAgt.substring(verOffset + 8);
    }
// MSIE 11+
    else if (nAgt.indexOf('Trident/') != -1) {
        browser = 'Microsoft Internet Explorer';
        version = nAgt.substring(nAgt.indexOf('rv:') + 3);
    }
// WeiXin
    else if (nAgt.indexOf('NetType/') != -1) {
        browser = 'WeiXin';
        if (nAgt.indexOf('NetType/WIFI') != -1) {
            network = 'WIFI';
        }else if(nAgt.indexOf('NetType/2G') != -1) {
            network = '2G';
        }else if(nAgt.indexOf('NetType/3G+') != -1) {
            network = '3G+';
        }
        verOffset = nAgt.lastIndexOf('/')
        version = nAgt.substring(verOffset + 1);
        if (browser.toLowerCase() == browser.toUpperCase()) {
            browser = navigator.appName;
        }
    }
// Other browsers
    else if ((nameOffset = nAgt.lastIndexOf(' ') + 1) < (verOffset = nAgt.lastIndexOf('/'))) {
        browser = nAgt.substring(nameOffset, verOffset);
        version = nAgt.substring(verOffset + 1);
        if (browser.toLowerCase() == browser.toUpperCase()) {
            browser = navigator.appName;
        }
    }

    // trim the version string
    if ((ix = version.indexOf(';')) != -1) version = version.substring(0, ix);
    if ((ix = version.indexOf(' ')) != -1) version = version.substring(0, ix);
    if ((ix = version.indexOf(')')) != -1) version = version.substring(0, ix);
    majorVersion = parseInt('' + version, 10);
    if (isNaN(majorVersion)) {
        version = '' + parseFloat(navigator.appVersion);
        majorVersion = parseInt(navigator.appVersion, 10);
    }

    // mobile version
    var mobile = /Mobile|mini|Fennec|Android|iP(ad|od|hone)/.test(nVer);

    // start system detect
    var os = '';
    var clientStrings = [
        {s: 'Windows 10', r: /(Windows 10.0|Windows NT 10.0)/},
        {s: 'Windows 8.1', r: /(Windows 8.1|Windows NT 6.3)/},
        {s: 'Windows 8', r: /(Windows 8|Windows NT 6.2)/},
        {s: 'Windows 7', r: /(Windows 7|Windows NT 6.1)/},
        {s: 'Windows Vista', r: /Windows NT 6.0/},
        {s: 'Windows Server 2003', r: /Windows NT 5.2/},
        {s: 'Windows XP', r: /(Windows NT 5.1|Windows XP)/},
        {s: 'Windows 2000', r: /(Windows NT 5.0|Windows 2000)/},
        {s: 'Windows ME', r: /(Win 9x 4.90|Windows ME)/},
        {s: 'Windows 98', r: /(Windows 98|Win98)/},
        {s: 'Windows 95', r: /(Windows 95|Win95|Windows_95)/},
        {s: 'Windows NT 4.0', r: /(Windows NT 4.0|WinNT4.0|WinNT|Windows NT)/},
        {s: 'Windows CE', r: /Windows CE/},
        {s: 'Windows 3.11', r: /Win16/},
        {s: 'Android', r: /Android/},
        {s: 'Open BSD', r: /OpenBSD/},
        {s: 'Sun OS', r: /SunOS/},
        {s: 'Linux', r: /(Linux|X11)/},
        {s: 'iOS', r: /(iPhone|iPad|iPod)/},
        {s: 'Mac OS X', r: /Mac OS X/},
        {s: 'Mac OS', r: /(MacPPC|MacIntel|Mac_PowerPC|Macintosh)/},
        {s: 'QNX', r: /QNX/},
        {s: 'UNIX', r: /UNIX/},
        {s: 'BeOS', r: /BeOS/},
        {s: 'OS/2', r: /OS\/2/},
        {s: 'Search Bot', r: /(nuhk|Googlebot|Yammybot|Openbot|Slurp|MSNBot|Ask Jeeves\/Teoma|ia_archiver)/}
    ];
    for (var id in clientStrings) {
        var cs = clientStrings[id];
        if (cs.r.test(nAgt)) {
            os = cs.s;
            break;
        }
    }
    var osVersion = '';
    if (/Windows/.test(os)) {
        osVersion = /Windows (.*)/.exec(os)[1];
        os = 'Windows';
    }
    switch (os) {
        case 'Mac OS X':
            osVersion = /Mac OS X (10[\.\_\d]+)/.exec(nAgt)[1];
            break;
        case 'Android':
            osVersion = /Android ([\.\_\d]+)/.exec(nAgt)[1];
            break;
        case 'iOS':
            osVersion = /OS (\d+)_(\d+)_?(\d+)?/.exec(nVer);
            osVersion = osVersion[1] + '.' + osVersion[2] + '.' + (osVersion[3] | 0);
            break;
    }

    //detect data
    var params = {};
    params.os = os;//操作系统
    params.osVersion = osVersion ? osVersion : 'unknown';//操作系统版本
    params.mobile = mobile;//是否移动端访问
    params.browser = browser;//浏览器
    params.browserVersion = version;//浏览器版本
    params.browserMajorVersion = majorVersion;//浏览器major版本

    //输出对象
    console.log(params);