let p = {name:'jack', age: 21}
console.log(p.name)
console.log(p['name'])

let names: Array<string> = ['a','b']
let age: number[] = [1,2]
console.log(names[1])

let num:number = 21
if(num%2===0){ // 推薦使用三個(gè)等于號(hào)判斷
    console.log("ou")
} else{
    console.log("ji")
}

for(let i=0;i<10;i++){
    console.log(i)
}
let num=0
while(num<10){
        console.log(num)
}

let names: Array<string> = ['a','b']
for(let i in names){
    console.log(i+':' names[i]) // 這種方取出來的是下標(biāo)
}
for(let n of names){
    console.log(n) // 這種方取出來的是一個(gè)個(gè)的元素
}

function sum(x: number, y: number): number {
    return x+y
}
let result = sum(1,2)
console.log('1+2=' + result)

let sayHi = (name: string) =>{
    console.log('hi' + name)
}
sayHi('Jack')

// 參數(shù)后加問號(hào)？，表示可選
function sayHi (name？: string) {
    name = name ? name: '無名氏' //判斷，沒有傳入?yún)?shù)就賦值
    console.log('hi' + name)
}
sayHi('Jack')
sayHi()

// 上述可賦默認(rèn)值 類似python語法
function sayHi (name: string = 'Jack')  //若不傳參 默認(rèn)為Jack

// 定義枚舉 不需要寫let和參數(shù)類型等
enum Msg{
    HI = 'hi',
    HELLO = 'hello'
}
// 定義接口
interface A{
    say(msg: Msg):void
}
// 實(shí)現(xiàn)接口
class B implements A{
    say(msg:Msg):void{
        console.log(msg + "ni hao")
    }
}
// 初始化對(duì)象 并調(diào)用方法
let a:A = new B()
a.say(Msg.HI)

// 定義矩形類
class Rectangle{
    // 定義成員變量 無需let
    private width: number
    private length: number
    //構(gòu)造函數(shù) 無需function
    constructor(width:number,length:number){
        this.length=length
        this.width=width
    }
    public area():number{
        return this.width*this.length
    }
}
// 定義正方形類，繼承于矩形類
class square extends Rectangle{
    constructor(side: number){
        super(side,side) //調(diào)用父類構(gòu)造函數(shù)
    }
}

let s = new square(10)
console.log('正方形面積：'+ s.area())

// 定義類，并通過export導(dǎo)出
export class Rectangle{
    xxx
}
//  定義工具方法
export function area(rec:Rectangle) number{
    xxx
}

// 通過import語法導(dǎo)入 from后寫地址
import {Rectangle, area} from '../rectangle'
// 使用導(dǎo)入的類創(chuàng)建對(duì)象
let r = new Rectangle(10,20)
// 調(diào)用導(dǎo)入的方法
console.log(area(r))