type

功能一、定義純文字

ts

AnimalStrings 是 型別

export enum AnimalEnum {
  Dog,
  Cat,
  Pig
}

type AnimalStrings = keyof typeof AnimalEnum;
// const a: AnimalStrings = 'Cat';

功能二、定義 new 型別

ts

// TypeScript 官網寫法，但 VS Code 給我毛毛蟲
interface AnimalConstructor {
    new(hp: number): AnimalInterface;
}

ts

// 無毛毛蟲版本
export type AnimalConstructor = new(hp: number) => AnimalInterface;

改寫自 TypeScript 範本 - 綜合版本

ts

interface AnimalInterface {
    call(): void;
}

interface AnimalConstructor {
    new(hp: number): AnimalInterface;
}

function createAnimal(ani: AnimalConstructor, hp: number): AnimalInterface {
    return new ani(hp);
}

class Human implements AnimalInterface {
    constructor(hp: number) {}
    call() {
        console.log("水之呼吸");
    }
}

class Dog implements AnimalInterface {
    constructor(hp: number) {}
    call() {
        console.log("旺旺");
    }
}

let human = creatAnimal(Human, 100);
let dog = creatAnimal(Dog, 30);

改寫來源 https://www.typescriptlang.org/docs/handbook/interfaces.html#class-types