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Can I Specify Parameter Type as One of Many Types Instead of Any Type in TypeScript?

rated 0 times [ 12] [ 2] / answers: 1 / hits: 88492 / 12 Years ago, mon, october 8, 2012, 12:00:00

In a method declaration in TypeScript, the parameter could be of type array of strings, booleans, or numbers. Do I have to declare it as any[] or is there a way to limit the input type as on of these three types?

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terrence

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answered 12 Years ago jeremiahianx · Accepted Answer

Typescript 1.4 introduced Union Types so the answer now is yes, you can.

function myFunc(param: string[] | boolean[] | number[]): void;

Using other type than the ones specified will trigger a compile-time error.

If you want an array of multiple specific types, you can use Union Types for that as well:

function myFunc(param: (string|boolean|number)[]): void;

Note that this is different from what OP asked for. These two examples have different meanings.