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maybe

  • Edit on GitHub

Create a strictly typed TypeObject that also accepts null and undefined values.

type.maybe(Type)

Given a type, returns a TypeObject that will check values against against that type. Throws if the value is not of the provided type or null or undefined.

import { Reflect, type } from "can/everything";

let val = Reflect.convert(42, type.maybe(Number));
console.log(val); // -> 42

val = Reflect.convert(null, type.maybe(Number));
console.log(val); // -> null

val = Reflect.convert(undefined, type.maybe(Number));
console.log(val); // -> undefined

Reflect.convert("42", type.maybe(Number));
// throws for providing an invalid type.

Parameters

  1. Type {function}:

    A constructor function that values will be checked against.

Returns

{TypeObject}:

A TypeObject which will enforce conversion to the given type.

CanJS is part of DoneJS. Created and maintained by the core DoneJS team and Bitovi. Currently 6.0.1.

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