类型注解

2023年06月27日

柏拉文

越努力，越幸运

一、构造函数

1.1 构造函数体

通用构造函数类型注解

class Person {
  public name: string;
  public age: number;
  constructor(name: string, age: number) {
    this.name = name;
    this.age = age;
  }
}
type ConstructorType<T> = new (...args:any[]) => T;
const PersonConstructor:ConstructorType<Person> = Person;

特定构造函数类型注解

通过 new 关键字对特定构造函数类型注解

class Person {
  public name: string;
  public age: number;
  constructor(name: string, age: number) {
    this.name = name;
    this.age = age;
  }
}
type PersonConstructorType = new (name:string,age:number) => Person;
const PersonConstructor:PersonConstructorType = Person;

通过 typeof 关键字对特定构造函数类型注解

class Person {
  public name: string;
  public age: number;
  constructor(name: string, age: number) {
    this.name = name;
    this.age = age;
  }
}
const PersonConstructor:typeof Person = Person;

1.2 构造函数参数

通过 infer P 获取构造函数参数，进而对构造函数参数进行类型注解

class Person {
  public name: string;
  public age: number;
  constructor(name: string, age: number) {
    this.name = name;
    this.age = age;
  }
}

type ConstructorType = new (...args: any[]) => any;
type ConstructorTypeT<T> = new (...args: any[]) => T;
type ConstructorParamsType<T extends ConstructorType> = T extends new (...args: infer P) => any ? P : any;

function createInstance<T>(constructor: ConstructorTypeT<Person>, ...args: ConstructorParamsType<typeof Person>) {
  return new constructor(...args)
}

const person = createInstance<Person>(Person,'柏拉图',23)

一、构造函数​

1.1 构造函数体​

1.2 构造函数参数​

一、构造函数

1.1 构造函数体

1.2 构造函数参数