min($arr); case 'max': return $this->max($arr); default: return null; } } private function min(array $arr) : mixed { $result = $arr[0]; foreach ($arr as $value) { if ($value < $result) { $result = $value; } } return $result; } private function max(array $arr) : mixed { $result = $arr[0]; foreach ($arr as $value) { if ($value > $result) { $result = $value; } } return $result; } }