javascript判断浏览器类型与版本

除了另无它法，肯定不使用navigator.userAgent来判定浏览器。因为在第一次浏览器大战初期，Netscape占绝对统计地位，大部分人们不愿意兼容其他浏览器，并通过检测其UA让他们的网站只允许Netscape访问，这就逼使其他浏览器（包括IE）修改自己的UA伪装成Netscape来通过那些自以为是的脚本，于是出现每个人都声称自己是别人的局面，即使最新的IE9的UA也是:

 
        //Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; Trident/5.0)

下面我收集或独创的一些判定：

 
//2010 4 16日更新
        ie = !+"\v1" ;
        ie = !-[1,];//IE9预览版中失效
        ie ='\v'=='v' ;
        ie = !!document.recalc
        ie = !!window.VBArray
        ie = !!window.ActiveXObject
        ie = 0//@cc_on+1;
        ie = !!window.createPopup;
        ie = /*@cc_on!@*/!1;
        ie = document.expando;//document.all在opera firefox的古老版本也存在
        ie = /\w/.test('\u0130') //由群里的abcd友情提供
       
        ie6 = !"1"[0] //利用IE6或IE5的字符串不能使用数组下标的特征
        ie8 = !!window.XDomainRequest;
        ie9 =  document.documentMode && document.documentMode === 9;
        //自创，基于条件编译的嗅探脚本，IE会返回其JS引擎的版本号，非IE返回0
        var ieVersion = eval("''+/*@cc_on"+" @_jscript_version@*/-0")*1
        ie9 = ieVersion === 5.9
        ie8 = ieVersion === 5.8
        ie7 = ieVersion === 5.7
        ie6 = ieVersion === 5.6
        ie5 = ieVersion === 5.5
        //https://developer.mozilla.org/En/Windows_Media_in_Netscape
        netscape = !!window.GeckoActiveXObject 
        gecko  = !!window.netscape //包括firefox
        firefox = !!window.Components
        firefox = !!window.updateCommands
        safari = !!(navigator.vendor && navigator.vendor.match(/Apple/))
        safari = window.openDatabase && !window.chrome;
        chrome= !!(window.chrome && window.google)
        opera=!!window.opera ;
        //傲游2 3
        maxthon = /maxthon/i.test(navigator.userAgent)
        //360安全浏览器
        is360se = /360se/i.test(navigator.userAgent)

 
//2010.6.4
       setTimeout(function(){//FF的setTimeout总是有一个额余的参数0
          var isFF = !!arguments.length;
          alert(isFF)
        }, 0);

 
//判定IE版本
2010.10.1
      ie = (function(undefined){
        var v = 3, div = document.createElement('div');
        while (
        div.innerHTML = '',
        div.getElementsByTagName('i')[0]);
        return v> 4 ? v : undefined;
      }());

 
//判定IE版本 2011.2.24
       ie = (function() {
          var v = 3, div = document.createElement('div'), a = div.all || [];
          while (div.innerHTML = '', a[0]);
          return v > 4 ? v : !v;
        }());

 
//手机的相关判定 2011.9.21
 isIPhone = /iPhone/i.test(navigator.userAgent);
 isIPhone4 = window.devicePixelRatio >= 2
//在网页中，pixel与point比值称为device-pixel-ratio，普通设备都是1，iPhone 4是2，有些Android机型是1.5
//http://blog.webcreativepark.net/2011/01/25-173502.html
 isIPad = /iPad/i.test(navigator.userAgent);
 isAndroid = /android/i.test(navigator.userAgent);
 isIOS = isIPhone  || isIPad ;

isMobile = isIOS || isAndroid ;