const str='你好'
const num=2
const boolean=true
const empty=null
const un=undefined
const obj={}
const arr=[]
const fun=function(){}
console.log(typeof str)
console.log(typeof num)
console.log(typeof boolean)
console.log(typeof empty)
console.log(typeof un)
console.log(typeof obj)
console.log(typeof arr)
console.log(typeof fun)