js之typeof与instanceof 小解

var a="TAO";
var b=true;
var c=10;
var d;
var e=null;
var f=new Object();

alert(typeof a); //string
alert(typeof b); //number
alert(typeof c); //boolean
alert(typeof d); //undefined
alert(typeof e); //object
alert(typeof f); //object
----------------------------------------------------------------------
var fun = function(){};
typeof fun
==>"function"
fun instanceof Function==>truefun instanceof Object==>true
var array=new Array();
var object=new Object();
var regexp=new RegExp();
function func(){};
var func1=new func();

alert(array instanceof Array);  //true
alert(object instanceof Object);  //true
alert(regexp instanceof RegExp);  //true
alert(func1 instanceof func);  //true

总之，typeof多用于基本数据类型如：string、number、boolean等类型的判断；
instanceof多用于引用类型如：Array、function等类型的判断；