EMACScript基本类型

根据ECMAScript最新规范的6.1的内容描述，现在ES的类型有Undefined, Null, Boolean, String, Symbol, Number, BigInt, and Object, 其中除了Object都是基本类型。

// 运行环境NodeJS V10.15.1
var primitiveTypeNumber = 1
var primitiveTypeBoolean = true
var primitiveTypeUndefined = undefined
var primitiveTypeNull = null
var primitiveTypeSymbol = Symbol(1)
var primitiveTypeBigInt = 1n
var primitiveTypeString = '123123'

console.log("primitiveTypeNumber: ", typeof primitiveTypeNumber) //primitiveTypeNumber:  number
console.log("primitiveTypeBoolean: ", typeof primitiveTypeBoolean) // primitiveTypeNumber:  number
console.log("primitiveTypeUndefined: ", typeof primitiveTypeUndefined) // primitiveTypeUndefined:  undefined
console.log("primitiveTypeNull: ", typeof primitiveTypeNull) // primitiveTypeNull:  object
console.log("primitiveTypeSymbol: ", typeof primitiveTypeSymbol) // primitiveTypeSymbol:  symbol
console.log("primitiveTypeBigInt: ", typeof primitiveTypeBigInt) // primitiveTypeBigInt:  bigint 
console.log("primitiveTypeString: ", typeof primitiveTypeString) // primitiveTypeString:  string