# Countable - `v::countable()` Validates if the input is countable, in other words, if you're allowed to use [count()](http://php.net/count) function on it. ```php v::countable()->validate([]); // true v::countable()->validate(new ArrayObject()); // true v::countable()->validate('string'); // false ``` *** See also: * [ArrayType](ArrayType.md) * [ArrayVal](ArrayVal.md) * [Instance](Instance.md) * [IterableType](IterableType.md)