[Home](./index.md) > [@apextoaster/js-utils](./js-utils.md) > [isNone](./js-utils.isnone.md) ## isNone() function Signature: ```typescript export declare function isNone(val: Maybe): val is None; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | val | [Maybe](./js-utils.maybe.md)<T> | | Returns: val is [None](./js-utils.none.md)