类型数组的Typescript接口 [英] Typescript interface from array type

问题描述

我需要强制数组具有一组特定的值，这些值应该是我接口的键.我可以用

I need to force an array to have a specific set of values that should be then the keys of my interface. I can force the array with

type SomeProperties = ['prop1', 'prop2', 'prop3'];

但是我不知道如何强制接口具有这些属性.我尝试过类似的

but I don't know how to force an interface to have those properties. I tried something like

type MyInterface = {
  [key in keyof SomeProperties]: string;
}

但是很明显，数组的键只是数字，所以我的界面变成了

but obviously the keys of an array are just numbers so my interface become

interface MyInterface {
  0: string;
  1: string;
  2: string;
}

代替所需的界面

interface MyInterface {
  prop1: string;
  prop2: string;
  prop3: string;
}

您知道在Typescript中是否有办法实现这一目标?

Do you know if there is a way to achieve this in Typescript?

这将很有用，因为我需要迭代某些属性以克隆"对象，并且还需要轻松访问这些属性.在类型和接口上重复属性对我来说有点脆弱.

It would be useful because I need to iterate on some properties to "clone" an object and I also need to access to those properties easily. Repeating the properties in both type and interface is a bit fragile for me.

推荐答案

您注意到，您尝试访问的字符串不是 SomeProperties 的 keys ，但 SomeProperties 的 elements .

As you note, the strings you're trying to access aren't the keys of SomeProperties, but the elements of SomeProperties.

您可以使用索引访问运算符此处:如果 K 是 T 的键(或键的并集)，则 T [K] 是属性类型(或并集属性类型)对应于访问 T 的 K 键.

You can use the indexed access operator here: if K is a key (or a union of keys) of T, then T[K] is the property type (or union of property types) corresponding to accessing the K key(s) of T.

组合和数组接受 number 作为键类型，因此您想使用 SomeProperties [number] 为您提供并集"prop1" |"prop2"|" prop3":

Tuples and arrays accept number as a key type, so you want to use SomeProperties[number] to give you the union "prop1"|"prop2"|"prop3":

type SomeProperties = ['prop1', 'prop2', 'prop3'];

type MyInterface = {
  [key in SomeProperties[number]]: string;
}

const myInterface: MyInterface = {
  prop1: 'this',
  prop2: 'works',
  prop3: 'now'
}

希望有所帮助；祝你好运！

Hope that helps; good luck!

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