[Home](./index.md) > [@apextoaster/js-utils](./js-utils.md) > [isNil](./js-utils.isnil.md) ## isNil() function Check if a value is nil. Signature: ```typescript export declare function isNil(val: Optional): val is Nil; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | val | [Optional](./js-utils.optional.md)<T> | | Returns: val is [Nil](./js-utils.nil.md)