How to define static variables in TypeScript

Question

I want to define an array with a constant value e.g. const arr = ["a", "b"];. However, the compiler will think it's string[]. Is there is a way to make it a constant type as is so the type of arr should be ["a", "b"]. The only way I found was to do like: const arr: ["a", "b"] = ["a", "b"];. but it's like code duplication.

Answer 1

You could define it as a read-only constant. Keep in mind that a constant can never be reassigned anyways.

const CHOICES = ['a', 'b'] as const;