javascript浏览器判断

function _browser() {
        var ieAX = window.ActiveXObject;
        var ieMode = document.documentMode;
        var ieVer = _getIeVersion() || ieMode || 0;
        var isIe = ieAX || ieMode;
        var chromiumType = _getChromiumType();

        return {
            isIE: (function () {
                return !!ieVer;
            })(),
            ieVersion: (function () {
                return ieVer;
            })(),
            isChrome: (function () {
                return chromiumType === ‘chrome‘;
            })(),
            is360se: (function () {
                return chromiumType === ‘360se‘;
            })(),
            is360ee: (function () {
                return chromiumType === ‘360ee‘;
            })(),
            isLiebao: (function () {
                return chromiumType === ‘liebao‘;
            })(),
            isSogou: (function () {
                return chromiumType === ‘sogou‘;
            })(),
            isQQ: (function () {
                return chromiumType === ‘qq‘;
            })()
        };


        /**
         * 检测 external 是否包含该字段
         * @param reg 正则
         * @param type 检测类型，0为键，1为值
         * @returns {boolean}
         * @private
         */
        function _testExternal(reg, type) {
            var external = window.external || {};

            for (var i in external) {
                if (reg.test(type ? external[i] : i)) {
                    return true;
                }
            }

            return false;
        }
        /**
         * 获取 Chromium 内核浏览器类型
         * @link http://www.adtchrome.com/js/help.js
         * @link https://ext.chrome.360.cn/webstore
         * @link https://ext.se.360.cn
         * @return {String}
         *         360ee 360极速浏览器
         *         360se 360安全浏览器
         *         sougou 搜狗浏览器
         *         liebao 猎豹浏览器
         *         chrome 谷歌浏览器
         *         ‘‘    无法判断
         * @version 1.0
         * 2014年3月12日20:39:55
         */
        function _getChromiumType() {
            if (isIe || typeof window.scrollMaxX !== ‘undefined‘) {
                return ‘‘;
            }

            var _track = ‘track‘ in document.createElement(‘track‘);
            var webstoreKeysLength = window.chrome && window.chrome.webstore ? Object.keys(window.chrome.webstore).length : 0;

            // 搜狗浏览器
            if (_testExternal(/^sogou/i, 0)) {
                return ‘sogou‘;
            }

            // 猎豹浏览器
            if (_testExternal(/^liebao/i, 0)) {
                return ‘liebao‘;
            }

            // chrome
            if (window.clientInformation && window.clientInformation.languages && window.clientInformation.languages.length > 2) {
                return ‘chrome‘;
            }


            if (_track) {
                // 360极速浏览器
                // 360安全浏览器
                return webstoreKeysLength > 1 ? ‘360ee‘ : ‘360se‘;
            }
            return ‘‘;
        }


        // 获得ie浏览器版本
        function _getIeVersion() {
            var v = 3,
                p = document.createElement(‘p‘),
                all = p.getElementsByTagName(‘i‘);

            while (
                p.innerHTML = ‘<!--[if gt IE ‘ + (++v) + ‘]><i></i><![endif]-->‘,
                    all[0]);

            return v > 4 ? v : 0;
        }
    }