[Home](./index.md) > [rc-js-util](./rc-js-util.md) > [arrayFlatMap](./rc-js-util.arrayflatmap.md) ## arrayFlatMap() function Iterate over `ArrayLike` calling a callback against it, the callback returns `ArrayLike` which is concatenated into a single `Array`. **Signature:** ```typescript export declare function arrayFlatMap(items: ArrayLike, mapCallback: (item: TItem, index: number) => ArrayLike | null): TTransformed[]; ``` ## Parameters

Parameter	Type	Description
items	ArrayLike<TItem>	The items to iterate over.
mapCallback	(item: TItem, index: number) => ArrayLike<TTransformed> \| null	The return from this callback is concatenated to the result, unless null is returned in which case the result is omitted.

**Returns:** TTransformed\[\] The output of `mapCallback` flattened into a single array. ## Remarks See [arrayFlatMap()](./rc-js-util.arrayflatmap.md).