Two way to get browser type[ and version]

browserinfo.js

var getBrowserInfo = function() {
    // Ref: http://www.useragentstring.com/pages/useragentstring.php
    var token = [ // 顺序有关
            "Opera", // 某些版本会伪装成 MSIE, Firefox
            "Chrome", // 某些版本会伪装成 Safari
            "Safari", // 某些版本会伪装成 Firefox
            "MSIE 6",
            "MSIE 7",
            "MSIE 8",
            "MSIE 9",
            "Firefox"
        ],
        ua = navigator.userAgent;

    for (var i = 0, len = token.length; i < len; ++i) {
        if(ua.indexOf(token[i]) != -1) {
            return token[i].replace(' ', '');
        }
    }
    return "Other";
};

var browser = (function() {
    var userAgent = navigator.userAgent;
    var regexs = [
        /MS(?:(IE) ([0-9]\.[0-9]))/,
        /(Chrome)\/([0-9]+\.[0-9]+)/,
        /(Firefox)\/([0-9a-z\.]+)/,
        /(Opera).*Version\/([0-9]+\.[0-9]+)/,
        /Version\/([0-9]+\.[0-9]+).*(Safari)/
    ];
    for (var i = 0; i < regexs.length; i++){
        var regex = regexs[i];
        var match = userAgent.match(regex);
        if (match){
            var results = match.slice(1);
            if (match.toString().indexOf('Safari') >= 0)
                results = [results[1], results[0]];
            return results.join(' ');
        }
    }
    return userAgent;
})();