typescript - 如何在 Typescript 中将缺少字段的对象转换为另一个对象？

Question

我在使用 Typescript 接口(interface)时遇到问题。我正在尝试将一个对象(缺少某些字段，例如 createdBy)转换到另一个对象，但我的转换不起作用。

我希望有人能提供帮助。

这是我拥有的接口(interface)文件:

interface IWord {
    ascii?: number;
    awl570?: boolean;
    awl570Sublist?: number;
    categoryId: number;
    frequency?: number;
    groupId: number;
    lessonId: number;
    name: string;
    nawl963?: boolean;
    nawl963D?: number;
    nawl963Sfi?: number;
    nawl963U?: number;
    statusId: number;
    syllables?: string;
    toeflMcG400?: boolean;
    toeic?: boolean;
    wordForms: IWordForm[];
    wordId: number;
    createdById: number;
    createdDate: string;
    modifiedById: number;
    modifiedDate: string;
}

interface IWordForm {
    definition: string;
    posId: number;
    sampleSentences: [ISampleSentence];
    sourceId: number;
    statusId: number;
    synonyms: [ISynonym];
    wordFormId: number;
    wordId: number;
    createdById: number;
    createdDate: string;
    modifiedById: number;
    modifiedDate: string;
}

我正在尝试创建这个:

var wos.word = <IWord>{
    categoryId: 1,
    lessonId: 1,
    name: null,
    groupId: 1,
    statusId: Status.Clean,
    toefl: true,
    wordForms: <IWordForm[]>[],
    wordId: $stateParams.wordId
}

但出现以下错误:

Severity Code Description Project File Line Suppression State Error TS2352 Neither type '{ categoryId: number; lessonId: number; name: null; groupId: number; statusId: Status; toefl: boo...' nor type 'IWord' is assignable to the other. Property 'createdById' is missing in type '{ categoryId: number; lessonId: number; name: null; groupId: number; statusId: Status; toefl: boo...'. admin C:\H\admin\admin\app\routes\words.ts 102 Active

Answer 1

有一个working playground example

嗯，因为表达式的赋值word = <IWord>{ ...}确实不包含 createdByID、createdDate、modifedById、modifiedDate，我们应该简单地让它们为空

interface IWord {
    ...
    createdById?: number;
    createdDate?: string;
    modifiedById?: number;
    modifiedDate?: string;
}

换句话说——要么我们要求 Typescript 为我们检查这些不能为空……然后我们必须提供它们。或者他们可能会丢失，那么上面的解决方案就是要走的路......

实际测试 here