How to get the type of an enum | TypeScript Community | Page 1

weary fern May 23, 2023, 1:14 AM

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If I have a function that uses an enum as a parameter, how can I get the type of that enum, so I can return a value of the same type?

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Let's say I have:

enum EFoo {
  VALE_1 = "Value 1",
  VALE_2 = "Value 2",
}

function test<O extends Object, K extends typeof O>(e: Object): K[] {
  // Do some things...
  // Return array of same type
}

const bar = test(EFoo); // Should be an array of type string

waxen void May 23, 2023, 1:29 AM

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Why is it array of type string?

weary fern May 23, 2023, 1:35 AM

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waxen void Why is it array of type string?

Because the values of the enum are strings

waxen void May 23, 2023, 1:36 AM

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They don't have to be strings

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Still not sure what exactly you want but maybe this:

function test<E extends Record<string, unknown>>(e: E): E[keyof E][] {}

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Do note that your function implementation might have issues if the enum isn't a string enum

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You can change it to Record<string, string> to only allow string enums to be passed in

#How to get the type of an enum