[Home](./index.md) > [@apextoaster/js-utils](./js-utils.md) > [isArray](./js-utils.isarray_1.md) ## isArray() function Wrapper for `Array.isArray` with better readonly type handling. Signature: ```typescript export declare function isArray(list: TVal | ReadonlyArray): list is ReadonlyArray; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | list | TVal \| ReadonlyArray<TVal> | | Returns: list is ReadonlyArray<TVal>