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typescript - 打字稿继承扩展属性

问题描述

好吧，我有两个对象用户和参与者的简单继承。

用户定义为


export type userDoc = {
  firstname: string
  lastname: string
  email: string
}

export class User {
  props: userDoc = {
      firstname: "",
      lastname: "",
      email: "", 
      {...}
  }
}

参与者（从用户继承）为

type participantDoc = {
    pseudonym: string
    karma: number
    impact: number
    level: number
    experience: number
  }

export class Participant extends User {
    props: participantDoc = {
      pseudonym: "",
      karma: 0,
      impact: 0,
      level: 0,
      experience: 0
    }
}

现在我希望实现的是在子类中扩展父类的属性。我正在使用道具，因为 mongodb 并且因为以这种方式分配它而不是 Object.assign() 更安全。

错误打字稿正在抛出：

TS2416: Property 'props' in type 'Participant' is not assignable to thesame property in base type 'User'.
  Type 'participantDoc' is missing the following properties from type 'userDoc': firstname, lastname, email, and 6 more.

标签： typescriptobjectinheritanceproperties

解决方案

你将不得不像在课堂上那样扩展道具的类型。

改变

export type participantDoc = {
    pseudonym: string
    karma: number
    impact: number
    level: number
    experience: number
}

至

export type participantDoc = {
    pseudonym: string
    karma: number
    impact: number
    level: number
    experience: number
} & userDoc

此外，如果您愿意将您的类型声明为接口，您可以这样做：

export interface userDoc {
  firstname: string
  lastname: string
  email: string
}

export interface participantDoc extends userDoc {
    pseudonym: string
    karma: number
    impact: number
    level: number
    experience: number
}

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