typeof

1、基本类型，数字Number,布尔Boolean,字符串String,undefied,

typeof 1;//numbertypeof true;//booleantypeof "";//stringtypeof zheng;//undefined

2、引用类型,{}，null,

typeof {};//objecttypeof null;//objecttypeof Math;//objecttypeof /zheng/gi;//object

3、函数对象

typeof Number;//functiontypeof Boolean;//functiontypeof String;//functiontypeof RegExp;//functiontypeof Date;//functiontypeof Error;//functiontypeof Function;//functionvar sayName = function{alert(this.name)};typeof sayName;//function