get array from const enum

[wangzhilongh]

I hope there is a way to get an array from const enum.

for example:

const enum gender{
male = 1,
female = 2,
}

I need to there is a way to get an array from the const enum gender, and the result like this:
[1,2]

Thanks a lot!

[wangzhilongh]

const enum gender{
male = 1,
female = 2,
}
const genderArray = gender.toArray() // maybe just like this.
console.log(genderArray) // [1,2]

[MartinJohns]

Duplicate of #21391.

[Harpush]

I am pretty sure he meant to allow some syntax that like const enum which is replaced with literal strings at runtime will be replaced with the literal array of the const enum options.
So if we have say:

const enum Test {
  A = 'a',
  B = 'b'
}
const values = valueof Test;

It will get compiled to const values = ['a', 'b']

[wangzhilongh]

Yes. Please implement it.
Thanks!

[fatcerberus]

It will get compiled to const values = ['a', 'b']

This would be type-directed emit, which is unlikely to be implemented. See point 5 at https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals#non-goals:

5. [Do not] Add or rely on run-time type information in programs, or emit different code based on the results of the type system. Instead, encourage programming patterns that do not require run-time metadata.

[Harpush]

@fatcerberus Which means const enum goes against it too... I believe its just an enhancement to the already existing functionality

[RyanCavanaugh]

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[HKhademian]

enum X { A='A', B='B'};
const enum Y { A='A', B='B'};

every enum is defining a group of related values

we can use them like:

const x:X = X.A;
const y:Y = Y.A;

compiles to

const x = X.A;
const y = 'A';

then it is logical to have also a way to access the whole group of values.
like:
const Xs = Object.values(X);
and (((or any other syntax which doesn't matter at all)))
const Ys = valuesof Y;
then they compile to:
const Xs = Object.values(X);
and
const Ys = ['A','B'];