在 Typescript 中，如果事先不知道对象的属性，您如何键入它？

Question

I'm relatively new to typescript so pardon me if I'm missing something obvious. I'm using typescript with ReactJS and I am trying to define types for an API response.

The API docs say there's a meta property which is an object but it's key/values can can't be predicted. ie

{
  ...
  meta: {
    property1: value1 //(can be string/number/array)
    property2: value2
    .
    .
    .
    propertyN: valueN
  }
}

How do I type this effectively? My eslint complaints when I try { meta: object } so I'm assuming that's no good.

Answer 1

Since you have no idea what it's going to contain, other than that it's going to be an object, you can use:

{ [key: string]: unknown };

It's not exactly effective - you'll have to do further explicit type-narrowing on every property value, but at least it's type safe (unlike any ).

Answer 2

如果您知道它can be string/number/array ，只需像这样定义它：

type MetaType = { [key: string]: string | number | any[] };