rc-js-util/docs/rc-js-util.arrayflatmap.md

A collection of TS and C++ utilities to help writing performant and correct applications, achieved through strict typing and (removable) invariant checking.

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## 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<TItem, TTransformed>(items: ArrayLike<TItem>, mapCallback: (item: TItem, index: number) => ArrayLike<TTransformed> | null): TTransformed[];
```

## Parameters

<table><thead><tr><th>

Parameter


</th><th>

Type


</th><th>

Description


</th></tr></thead>
<tbody><tr><td>

items


</td><td>

ArrayLike&lt;TItem&gt;


</td><td>

The items to iterate over.


</td></tr>
<tr><td>

mapCallback


</td><td>

(item: TItem, index: number) =&gt; ArrayLike&lt;TTransformed&gt; \| null


</td><td>

The return from this callback is concatenated to the result, unless null is returned in which case the result is omitted.


</td></tr>
</tbody></table>
**Returns:**

TTransformed\[\]

The output of `mapCallback` flattened into a single array.

## Remarks

See [arrayFlatMap()](./rc-js-util.arrayflatmap.md)<!-- -->.