What is the method for determining the data type of a key within an interface?

Question

How do I retrieve the data type of User.name?

interface User {
  id: number;
  name: string;
}

I am looking to specify my other type as follows.

type UserInstance {
  name: <infer type "string" from User interface>;
  ...
}

The goal is to ensure flexibility: If the type "string" changes in the future, I won't have to update it in multiple places.

Answer 1

Answer №1

Get the specific property by using bracket notation as shown below (as mentioned in the question comments):

interface User {
  id: number;
  name: string;
}

type UserInstance = {
  name: User["name"]
}

Answer 2

Get the specific property by using bracket notation as shown below (as mentioned in the question comments):

interface User {
  id: number;
  name: string;
}

type UserInstance = {
  name: User["name"]
}

Answer 3

Here are a couple of methods to try out:

First: it is not recommended to use USER.name = (((everything you want))). If an error occurs, it will indicate the type based on the error details.

Second: highlight the word (((USER.na》|《me))) and press F12 to view its reference or type it directly.

The 》|《 represents your mouse cursor. Simply select the words ((name)) or ((USER)) where they are being used

Answer 4

Here are a couple of methods to try out:

First: it is not recommended to use USER.name = (((everything you want))). If an error occurs, it will indicate the type based on the error details.

Second: highlight the word (((USER.na》|《me))) and press F12 to view its reference or type it directly.

The 》|《 represents your mouse cursor. Simply select the words ((name)) or ((USER)) where they are being used