JS全兼容检测浏览器类型及版本

<script>
        var browser = (function () {
            var isIE6 = /msie 6/i.test(navigator.userAgent);
            var isIE7 = /msie 7/i.test(navigator.userAgent);
            var isIE8 = /msie 8/i.test(navigator.userAgent);
            var isIE9 = /msie 9/i.test(navigator.userAgent);
            var isIE = /msie/i.test(navigator.userAgent);
            var isFireFox = /firefox/i.test(navigator.userAgent);
            var isChrome = /Chrome/i.test(navigator.userAgent);
            return {
                msie: isIE,
                version: function () {
                    switch (true) {
                        case isIE6: return 6;
                        case isIE7: return 7;
                        case isIE8: return 8;
                        case isIE9: return 9;
                        case isFireFox: return "火狐";
                        case isChrome: return "谷歌";
                    }
                }()
            };
        })();
        alert(browser.msie);
        alert(browser.version);
</script>