js判断浏览器种类以及版本号（从jquery1.8中抠出来的）

 1 var myLibs = {
 2     // Use of jQuery.browser is frowned upon.
 3     // More details: http://api.jquery.com/jQuery.browser
 4     // jQuery.uaMatch maintained for back-compat
 5     browser:(function(){  
 6         var uaMatch = function(ua){
 7             ua = ua.toLowerCase();
 8     
 9             var match = /(chrome)[ /]([w.]+)/.exec( ua ) ||
10                 /(webkit)[ /]([w.]+)/.exec( ua ) ||
11                 /(opera)(?:.*version|)[ /]([w.]+)/.exec( ua ) ||
12                 /(msie) ([w.]+)/.exec( ua ) ||
13                 ua.indexOf("compatible") < 0 && /(mozilla)(?:.*? rv:([w.]+)|)/.exec( ua ) ||
14                 [];
15         
16             return {
17                 browser: match[ 1 ] || "",
18                 version: match[ 2 ] || "0"
19             };
20         };
21          
22         var matched = uaMatch(navigator.userAgent),
23             browser = {};
24         
25         if (matched.browser){
26             browser[matched.browser] = true;
27             browser.version = matched.version;
28         }
29         
30         // Chrome is Webkit, but Webkit is also Safari.
31         if (browser.chrome){
32             browser.webkit = true;
33         }else if (browser.webkit){
34             browser.safari = true;
35         }
36         return browser;  
37     })()
38 };
39 
40 console.log(myLibs.browser.mozilla);//true
41 console.log(myLibs.browser.version);//39.0