Converting a Typescript array of objects to an object

Question

I have this object type

interface MyObject<T> {
  id: string
  value: T
}

And this array type

type MyArray = MyObject[]

Now i need to declare a generic type that defines a new object based on ids and values in the MyObject's in the MyArray. In my mind in should look something like this, but i am not sure what to put inside the {{}}'s.

interface MyArrayObject<MyArray> {
    [id: {{MyArray[number].id}} ]: {{typeof MyArray[number].value}}
}

Example

const arr = [
  { id: "key1", value: 123 },
  { id: "key2", value: "abc" }
]

The resulting object contains all MyObject.ids and their respective MyObject.value.

const arrObject = {
  "key1": 123
  "key2": "abc" 
}

Is it even possible to type this?

You cannot strongly type *each* of the keys based on the array contents. Typescript types are compile time constructs (i.e. you "run" JavaScript). — crashmstr, Jun 06 '22 at 12:58
See [this](https://tsplay.dev/wRGnvN) example. If it works for you I will provide an answer — captain-yossarian from Ukraine, Jun 06 '22 at 12:59
@captain-yossarianfromUkraine Thank you! This is exactly what i need, although its slightly more complex than anticipated ;) — Jonas Littau, Jun 06 '22 at 13:07
Can I mark your question as a duplicate ? As you might have noticed, you can `reduce` your tuple in two ways: fist is a recursive type just like in linked answer and the second one with using `UnionToIntersection` and simple iteration through array keys — captain-yossarian from Ukraine, Jun 06 '22 at 13:08

Converting a Typescript array of objects to an object

Example

0 Answers0