| typeof | |
|---|---|
| Undefined | "undefined" |
| Null | "object" |
| Boolean | "boolean" |
| Number | "number" |
| String | "string" |
| Symbol | "symbol" |
| 函數(shù)對(duì)象 | "function" |
| 其它對(duì)象 | "object" |
instanceof 運(yùn)算符用于測(cè)試構(gòu)造函數(shù)的 prototype 屬性是否出現(xiàn)在對(duì)象的原型鏈中的任何位置
a = new Number(5)
a instanceof Number // true
a instanceof Object // true
