# callback

Checks with the callback sent by the user It's ideal for one-time custom validations

****

- Source: <https://github.com/getkirby/kirby/tree/5.5.3/src/Toolkit/V.php#L302>

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```php
V::callback($value, callable $callback): bool
```

## Parameters

| Name | Type | Default | Description |
| ---- | ---- | ---- | ---- |
| `$value` (required) | `mixed` | – | – |
| `$callback` (required) | `callable` | – | – |

## Return type

`bool`

## In your code

```php
V::callback(
	['green', 'blue'],
	fn ($value) => count($value) === count(array_intersect($value, ['red', 'green', 'blue']))
);
```