think\Validate::min PHP Method

    protected function min($value, $rule)
    {
        if (is_array($value)) {
            $length = count($value);
        } elseif ($value instanceof File) {
            $length = $value->getSize();
        } else {
            $length = mb_strlen((string) $value);
        }
        return $length >= $rule;
    }