通常用typeof来判断js变量的类型，但很多时候仅仅typeof满足不了要求的。
我写了一个自定义函数来做这个事，判断的比较全面了。
New
function varType(v){
if(typeof v==="object"){
if(v===null)return 'null';
if(v.constructor)
return (v.constructor.toString()).match(/(?: )[/w/$]+/)[0];
if(typeof typeof2==='undefined' && window.execScript){
window.execScript('Function vbsTypeName(o):vbsTypeName=TypeName(o):End Function','vbscript');
window.execScript('function typeof2(o){return vbsTypeName(o)}','jscript');
}
if(typeof typeof2!=='undefined'){
return typeof2(v);
}
return "object";
}
return typeof v;
}
//对于普通js常量和js对象，各浏览器是基本一致的
alert(varType()); //undefined
alert(varType(100)); //number
alert(varType({})); //Object
alert(varType([])); //Array
alert(varType(/ /)); //RegExp
alert(varType(new Date())); //Date
alert(varType(Date)); //function
alert(varType(Object)); //function
alert(varType(RegExp)); //function
//对于DOM对象，各浏览器可能会有不同值
alert(varType(window)); //IE:HTMLWindow2 FF:Window
alert(varType(document)); //IE:HTMLDocument FF:HTMLDocument
alert(varType(document.body)); //IE:HTMLBody FF:HTMLBodyElement
alert(varType(Option)); //IE:Object FF:function
alert(varType(Image)); //IE:Object FF:function
alert(varType(navigator)); //IE:DispHTMLNavigator FF:Navigator
//以下几个只适用于IE，其他内核浏览器不支持
alert(varType(ActiveXObject)); //IE:function
alert(varType(Enumerator)); //IE:function
alert(varType(new ActiveXObject("Scripting.Dictionary"))); //IE:Dictionary
alert(varType(new Enumerator())); //IE:Enumerator