> For the complete documentation index, see [llms.txt](https://arrayutils.docs.present.kim/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://arrayutils.docs.present.kim/methods/g/first/key.md).

# keyFirst()

The keyFirst() method returns first key

{% code title="Example.php" %}

```php
<?php use kim\present\utils\arrays\ArrayUtils;

$arrayUtils = ArrayUtils::from(["Apple" => 0, "Banana" => 1, "Carrot" => 2]);

//Gets first key
$arrayUtils->keyFirst();
// expected output: "Apple"
```

{% endcode %}

## Syntax

```php
$arrayUtils->keyFirst() : int|string|null;
```

### Return value

* A first key of array. If array is empty, returns `NULL`.

## Prefixing

```php
ArrayUtils::keyFirstFrom(iterable $from) : int|string|null;
```

## References

{% embed url="<https://www.php.net/manual/en/function.array-key-first>" %}