Number type to custom type of number

Question

I created a simple type:

export type CustomType = 0 | 1 | 2 | 3 | 4 | 5;

Now I want to initialize an already declared variable (current value = 0) of this type with the result of

Math.floor(Math.random() * 6)

Now, TypeScript tells me, that the Type number is not assignable to Type CustomType, even though the initialization should work as long the number is a whole number of 0, 1, 2, 3, 4, or 5.:

TS2322: Type 'number' is not assignable to type 'CustomType'.

Unfortunately, I failed to find any solution thus far. Casting to standard types is fine, but I am unsure how to make my custom type accept a number. Thank you in advance.

Does this answer your question? [Typescript Type 'string' is not assignable to type](https://stackoverflow.com/questions/37978528/typescript-type-string-is-not-assignable-to-type) — outis, Oct 05 '21 at 12:10

score 2 · Accepted Answer · answered Oct 05 '21 at 11:48

2

You can use a type assertion like this:

const value = Math.floor(Math.random() * 6) as CustomType;

answered Oct 05 '21 at 11:48

H.B.

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Thank you very much, did not know of the "of" keyword. Will take a look at it immediately.Will also mark as answer as soon as StackOverflow lets me. – 0kMike Oct 05 '21 at 11:51
@0kMike don't forget to upvote this answer if it was helpful. – captain-yossarian from Ukraine Oct 05 '21 at 11:57
I did, but this account does not have 15 reputation yet. Edit: nvm now it has – 0kMike Oct 05 '21 at 11:58
@0kMike you already have :D – captain-yossarian from Ukraine Oct 05 '21 at 11:58

Number type to custom type of number

1 Answers1