I want to make a list or array from all possible variants of a custom type.
Ex. The custom type:
export type FruitType= 'Apple' | 'Orange' | 'Strawberry' | 'Banana';
Wanted result:
const FruitArray = ['Apple', 'Orange', 'Strawberry', 'Banana']
Is this achievable or is hardcoding the list the only way?
I'm working in React with typescript
As TypeScript is just transpiled to JavaScript, the type information is only available at compile time, not at run time. You will have to re-define the value somewhere they're available at run time.
What you can do is define the array and then define a type based on it:
const fruitArray = ['Apple', 'Orange', 'Strawberry', 'Banana'] as const;
type FruitType = typeof fruitArray[number];
const fruit: FruitType = 'Apple';
However, FruitType will only allow values that are actually hard-coded into fruitArray from the very beginning.
If you can use enum instead type then you can write the next code:
enum FruitType {
Apple = 'Apple',
Orange = 'Orange',
Strawberry = 'Strawberry',
Banana = 'Banana',
}
const array = Object.values(FruitType);
