Question

我一直在寻找解决方案，但是我的代码似乎超出了标准的“将对象推入数组”范围。

我有一个接口，它使用另一个接口作为数组键入“年”属性：

   export interface IUser {
        Nickname: string;
        FirstName: string;
        LastName: string;
        Email: string;
        EmergencyContact: string;
        EmergencyNumber: string;
        Year: Array<IYear>;
        IsTeacher: boolean;
        IsAdmin: boolean;
        Uid: string;
    }

    export interface IYear {
        CalendarYear: string;
        PassType: string;
        UserItinerary: IItinerary;
        WaiverStatus: boolean;
        Guests: Array<IGuest>;
        SignupDate: string;
    }

在某个时候，我将一些formGroup数据传递给IYear类型的属性：

user: IUser = <IUser>{};

createUser(
    firstName: string,
    lastName: string,
    email: string,
    uid: string,
    isTeacher: boolean,
    passType: string) {
    const year: IYear = {
      CalendarYear: this.calendarYear,
      PassType: passType,
      UserItinerary: {} as IItinerary,
      WaiverStatus: false,
      Guests: [],
      SignupDate: this.dateTime
    }
    this.user.FirstName = firstName;
    this.user.LastName = lastName;
    this.user.Email = email;
    this.user.Uid = uid;
    this.user.IsTeacher = isTeacher;
    this.user.IsAdmin = false;
    this.user.Year.push(year);

    return this.user;
  }

问题是，当我尝试将createUser内的'year'属性传递到'this.user.Year'数组时，出现错误

无法读取未定义的属性“ push”

我尝试通过键显式传递值：

this.user.Year['CalendarYear'] = year.CalendarYear;

但是那没有用。有人可以在这里指出我的错误吗？

Answer 1

在将对象推入用户对象之前，应将用户对象中的Year数组初始化为空。

this.user.Year = [];

然后

this.user.Year.push(year);

Answer 2

出现错误的原因是，您必须首先初始化一个数组，然后可以push()为其赋值。

可以使用IUser初始化一个新的year = [{your year}]，然后然后将更多的值推入其中。
或使用空数组年份初始化一个新的IUser对象，然后然后将值推入该对象。

Answer 3

您已经在使用数组之前对其进行了初始化。

user: IUser = <IUser>{};    
createUser(
    firstName: string,
    lastName: string,
    email: string,
    uid: string,
    isTeacher: boolean,
    passType: string) {
    const year: IYear = {
      CalendarYear: this.calendarYear,
      PassType: passType,
      UserItinerary: {} as IItinerary,
      WaiverStatus: false,
      Guests: [],
      SignupDate: this.dateTime
    }
    this.user.FirstName = firstName;
    this.user.LastName = lastName;
    this.user.Email = email;
    this.user.Uid = uid;
    this.user.IsTeacher = isTeacher;
    this.user.IsAdmin = false;
    this.user.Year=[];
    this.user.Year.push(year);    
    return this.user;
  }

Answer 4

您需要确保Year存在于用户对象上，并且CalendarYear也存在于Year对象上

将对象推入嵌套的Typescript数组中，得到错误：无法读取未定义的属性“ push”

4 个答案: