1.typeof操作符，返回值为字符串,用来判断一个值是哪种基本类型

“undefined”-Undefined

"boolean"-Boolean

"string"-String

"number"-Number

"object"-Object或Null

"function:-Function

2.instanceof操作符,返回true/false,确定一个值是哪种引用类型.

console.log(Object instanceof Object);//true

console.log(Function instanceof Function);//true

console.log(Number instanceof Number);//false

console.log(String instanceof String);//false

console.log(Array instanceof Array);//false

console.log(Function instanceof Object);//true