js判断浏览器种类以及版本号（从jquery1.8中抠出来的）

var myLibs = {
    // Use of jQuery.browser is frowned upon.
    // More details: http://api.jquery.com/jQuery.browser
    // jQuery.uaMatch maintained for back-compat
    browser:(function(){  
        var uaMatch = function(ua){
            ua = ua.toLowerCase();
    
            var match = /(chrome)[ /]([w.]+)/.exec( ua ) ||
                /(webkit)[ /]([w.]+)/.exec( ua ) ||
                /(opera)(?:.*version|)[ /]([w.]+)/.exec( ua ) ||
                /(msie) ([w.]+)/.exec( ua ) ||
                ua.indexOf("compatible") < 0 && /(mozilla)(?:.*? rv:([w.]+)|)/.exec( ua ) ||
                [];
        
            return {
                browser: match[ 1 ] || "",
                version: match[ 2 ] || "0"
            };
        };
         
        var matched = uaMatch(navigator.userAgent),
            browser = {};
        
        if (matched.browser){
            browser[matched.browser] = true;
            browser.version = matched.version;
        }
        
        // Chrome is Webkit, but Webkit is also Safari.
        if (browser.chrome){
            browser.webkit = true;
        }else if (browser.webkit){
            browser.safari = true;
        }
        return browser;  
    })()
};

console.log(myLibs.browser.mozilla);//true
console.log(myLibs.browser.version);//39.0