javascript的几种基本类型：
- null
- undefined
- Boolean
- string
- Number
- Object
我看到网上一篇文章说是typeof无法判断function，可是为什么我试验了一下是可以判断的呢？不懂，欢迎各位看到有什么问题可以留言哦
var b=function(){console.log(999);}
typeof b
"function"
Object.prototype.toString.call(b)
"[object Function]"
array:typeof无法判断array倒确实,用Obeject.prototype.toString.call()
var a=new Array(1,2,3);
undefined
a
[1, 2, 3]
typeof a
"object"
Object.prototype.toString(a);
"[object Object]"
null:
typeof null
"object"
Object.prototype.toString.call(null)
"[object Null]"
Date:
var a=new Date()
undefined
a
Mon Aug 29 2016 14:11:45 GMT+0800 (CST)
typeof a
"object"
Object.prototype.toString.call(a)
"[object Date]"
HTMLCollection:
var a=document.getElementsByTagName('div');
undefined
Object.prototype.toString.call(a)
"[object HTMLCollection]"