TypeScript

interface 接口

// duck typing
interface LikeArray {
    [index: number]: string
}

Class

• constructor
• extends
• super
• public
• private
• protected

interface Aaa {
    currentTime:number;
    alert():void
}
class Clock implements Aaa{
    currentTime:number = 123,
    alert(){
    }
}

泛型

function withAPI<T>(url:string):Promise<T> {
    return fetch(url).then(res=>{
        resp.json())
    })
}

withAPI<Aaa>('country.resp')

交叉,联合类型

• &
• |

类型断言

• as

Partial

• 接受泛型,传入类型都变成可选

type Partial<T> = {
    [P in keyof T]?: T[P]
}

type CountOpt = {
    [p in Keys]?: CountOpt[p]
}

extends

• 是否满足约束
• 可以用在泛型 或者 条件类型

declare

declare var Jquery:(select:string)=>any)