rc-js-util/docs/rc-js-util.arrayunion.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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## arrayUnion() function

Given an `ArrayLike` of `ArrayLike`<!-- -->, provides all unique items in an `Array`<!-- -->.

**Signature:**

```typescript
export declare function arrayUnion<TItem>(items: ArrayLike<ArrayLike<TItem>>, getComparisonValue?: (item: TItem, index: number) => unknown): TItem[];
```

## Parameters

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

Parameter


</th><th>

Type


</th><th>

Description


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

items


</td><td>

ArrayLike&lt;ArrayLike&lt;TItem&gt;&gt;


</td><td>


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

getComparisonValue


</td><td>

(item: TItem, index: number) =&gt; unknown


</td><td>

_(Optional)_


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

TItem\[\]

## Remarks

See [arrayUnion()](./rc-js-util.arrayunion.md)<!-- -->.