# In - `v::in(mixed $haystack)` - `v::in(mixed $haystack, boolean $identical = false)` Validates if the input is contained in a specific haystack. For strings: ```php v::in('lorem ipsum')->validate('ipsum'); // true ``` For arrays: ```php v::in(['lorem', 'ipsum'])->validate('lorem'); // true ``` A second parameter may be passed for identical comparison instead of equal comparison. Message template for this validator includes `{{haystack}}`. *** See also: * [Contains](Contains.md) * [EndsWith](EndsWith.md) * [Roman](Roman.md) * [StartsWith](StartsWith.md)