javascript browser浏览器类型以及版本判断代码

/** 
* @author sky 
*/ 
var browser = function() 
{ 
//默认为ie6 
var _a = ["ie", "6", "6.0"]; 
var _s = false; 
var _ua = navigator.userAgent.toLowerCase(); 
//检测正则 
var _pat = { 
opera: /opera.([\d.]+)/, 
ie: /msie ([\d.]+)/, 
ff: /firefox\/([\d.]+)/, 
chrome: /chrome\/([\d.]+)/, 
safari: /safari\/([\d.]+)/, 
mozilla: /rv:([\d.]+).+gecko/ 
}; 
for (var _t in _pat) 
{ 
var _s = _ua.match(_pat[_t]); 
if (_s) 
{ 
_a = [_t, parseInt(_s[1]), _s[1]]; 
break; 
} 
} 
return _a; 
}(), 
 
简单演示：上面的代码应该框架中多个方法的一个 
 
<script> 
var browser = function() 
{ 
//默认为ie6 
var _a = ["ie", "6", "6.0"]; 
var _s = false; 
var _ua = navigator.userAgent.toLowerCase(); 
//检测正则 
var _pat = { 
opera: /opera.([\d.]+)/, 
ie: /msie ([\d.]+)/, 
ff: /firefox\/([\d.]+)/, 
chrome: /chrome\/([\d.]+)/, 
safari: /safari\/([\d.]+)/, 
mozilla: /rv:([\d.]+).+gecko/ 
}; 
for (var _t in _pat) 
{ 
var _s = _ua.match(_pat[_t]); 
if (_s) 
{ 
_a = [_t, parseInt(_s[1]), _s[1]]; 
break; 
} 
} 
return _a; 
}() 
var dd =browser; 
alert(dd[0]+" "+dd[1]+" "+dd[2]); 
</script> 

  [Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]