原始数据类型

let isDone: boolean = false
let age: number = 10
let firstName: string = 'viking'
let message: string = `Hello, ${firstName}`
let u: undefined = undefined
let n: null = null

Any类型(任意类型)

let notSure: any = 4
notSure = 'maybe a string'
notSure = true
notSure.myName
notSure.getName()