转一个js类型判断函数,支持返回dom 元素的类型,像HTMLBody

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
alert(varType(document.getElementsByTagName('DIV')[0]));