# $listItems->__isset()

> Checks if the current key is set

- Source: `src/Toolkit/Iterator.php#L160` <https://github.com/getkirby/kirby/blob/6.0.0-beta.1/src/Toolkit/Iterator.php#L160>
- Inherited from Kirby, not part of the Merx API. See <https://getkirby.com/docs/reference>.

```php
$listItems->__isset( $key): bool
```

## Parameters

| Name | Type | Default |
| --- | --- | --- |
| `$key` | `–` | `–` |

## Return type

`bool`

## Parent class

`Wagnerwagner\Merx\ListItems` inherited from `Kirby\Toolkit\Iterator`