[ExtJS]判断浏览器及操作系统的代码

[ExtJS]判断浏览器及操作系统的代码

var ua = navigator.userAgent.toLowerCase(),
        check = function(r){
            return r.test(ua);
        },
        isOpera = check(/opera/),
        isChrome = check(/chrome/),
        isWebKit = check(/webkit/),
        isSafari = !isChrome && check(/safari/),
        isSafari3 = isSafari && check(/version\/3/),
        isSafari4 = isSafari && check(/version\/4/),
        isIE = !isOpera && check(/msie/),
        isIE7 = isIE && check(/msie 7/),
        isIE8 = isIE && check(/msie 8/),
        isIE6 = isIE && !isIE7 && !isIE8,
        isGecko = !isWebKit && check(/gecko/),
        isGecko3 = isGecko && check(/rv:1\.9/),
        isBorderBox = isIE && !isStrict,
        isWindows = check(/windows|win32/),
        isMac = check(/macintosh|mac os x/),
        isAir = check(/adobeair/),
        isLinux = check(/linux/);