// teconfig.json
{
    "compilerOptions": {
        "watch": true,
        "removeComments": true,
        "target": "es5",
        "noImplicitAny": true,
        "strictNullChecks": true
    }
}

npm i typescript ts-node -g
tsc -v

# 编译执行
tsc xx.ts
node xx.ts

# 自动更新
ts-node xx.ts

let age:number = 10

// string
let str1:string = 'str'
let str2:string = `${variable} str`

// number
let num1:number = NaN
let num2:number =  Infinity // 无穷大
let num3:number = 0b1010    // 二进制
let num4:number = 0o744     // 八进制
let num5:number = 123       // 十进制
let num6:number = 0xf00d    // 十六进制

// bool
let bool:boolean = true

//void
let none:void = undefined
let none:void = null

let none:undefined = undefined
let none:null = null
// undefined 和 null 是所有类型的子类型

let a1:any = 123
let a2:any = "233"

a1 = a2

let obj:any = { b: 333}
obj.a
// 上述语句可执行，且不报错
// any类型在对象没有相应属性时，不会报错

let a
a = 233
a = '233'

let unknown:unknown = {a:233}
unknown.a  
// unknown 无法调用a
// unknown不能调用属性和方法

let str1:unknown = '233'
let str2:string = '233'
str2 = str1
// 报错，unknown 作为父类型无法赋值给子类型

let a2:number[] = [233]
// 基本定义

interface A1{
    [index: number]: number
}
let a1:A1 = [1,2,3]
// 类数组

let a3:Array<number> = [1,2]
// 泛型数组

let a4:[][] = [[2,2]]
// 多维数组

// method type
function getNumber(num:number):number {
    return num
}

// 函数表达式？ 匿名函数
const getNumber = (num: number) => number = (num) => {
    return num
}

// return void
function logNumber(num: number):void {
    console.log(num)
}

// 可选参数：声明必须位于参数项最后
function logInfo(info?: string = 'hello world'):void {
    console.log(info)
}

let obj4:object = 233
// 报错

let obj1:object = []
let obj2:object = {}
let obj3:object =  = () => 233

let a1:Object = 233
let a2:Object = []
let a3:Object = {}
let a4:Object = () => 233

let a5:{} = obj
// 字面量类型，创建后无法修改
// 这个也是Object类型

interface Person {
    name: string
    say: () => void
}

let son:Person = {
    name: 'son'
} // error

let son:Person = {
    name: 'son'
    say: () => {}
}

interface Fn {
    (name:string): number // 定义方法
}

let func:Fn = function (){
    return 233
}

interface Person {
    name:string
    [propName:string]:any
}

let son:Person = {
    name: '233'
    agt: 23
    height: 23
}

interface Person {
    readonly id: number  // readonly
    name: string
    age?: number         // 可选类型
}

interface Person extends B {
    name: string
    say: () => void
}
interface Person {
    talk: string
}
// 重名接口将合并

interface B {
    lol: string
}