js判断手机是的操作系统

 1 var browser = {
 2                 versions: function() {
 3                     var u = navigator.userAgent,
 4                     app = navigator.appVersion;
 5                     return {
 6       
 7                         android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1,
 8 
 9                         iPhone: u.indexOf('iPhone') > -1 ,                      
10 
11                         iPad: u.indexOf('iPad') > -1,
12                         iPod: u.indexOf('iPod') > -1,
13    
14                     };
15                 } (),
16                 language: (navigator.browserLanguage || navigator.language).toLowerCase()
17             }
18             if (browser.versions.iPhone||browser.versions.iPad||browser.versions.iPod)
19             {
20                 alert("apple")
21             }
22             else if(browser.versions.android)
23             {
24                alert("Android");
25             }  else{
26                 alert("other");
27             }