public static function arrayChangeCaseKey($array, $case = CASE_LOWER)
    {
        return array_map(function ($item) use ($case) {
            if (is_array($item)) {
                $item = self::arrayChangeCaseKey($item, $case);
            }

            return $item;
        }, array_change_key_case($array, $case));
    }
public static function arrayChangeCaseKey($array, $case = CASE_LOWER)
    {
        return array_map(function ($item) use ($case) {
            if (is_array($item)) {
                $item = self::arrayChangeCaseKey($item, $case);
            }

            return $item;
        }, array_change_key_case($array, $case));
    }
public static function arrayChangeCaseKey ( $ array , $ case = CASE_LOWER ) { return array_map ( function ( $ item ) use ( $ case ) { if ( is_array ( $ item ) ) { $ item = self :: arrayChangeCaseKey ( $ item , $ case ) ; } return $ item ; } , array_change_key_case ( $ array , $ case ) ) ; }
Changes the case of all keys in an array.

@param array  $array The array to work on.
@param string $case  Either CASE_UPPER or CASE_LOWER (default).

@since 3.0.0

@return array
Changes the case of all keys in an array .