function that return duplicate elements from an array

/**
 * Return an array containing only the element 'key => value' that are duplicated in the original $array.
 * Warning : the generated array DOES NOT respect the order of the original array.
 * @param $array
 *
 * @return array
 * @licence Copyright (C) 2015 Alexandre Bonneau
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
public static function arrayDuplicates($array) {
	$keyArr = [];
	$valArr = [];
	$dupeArr1 = [];

	foreach ($array as $key => $val) {
		if (in_array($key, $keyArr)) {
			$dupeArr1[$key] = $val;
		}
		else if (in_array($val, $valArr)) {
			$dupeArr1[$key] = $val;
		}
		$keyArr[] = $key;
		$valArr[] = $val;
	}

	$result = $dupeArr1;
	foreach ($dupeArr1 as $key => $val) { //I add the very first key=>value pair for the original array for each key=>value pair found in the array of duplicates
		/*
		 * Note : If the original array has duplicated key=>value elements, the first 'element' is copied that number of times. But duplicate keys in an array is unlikely, so osef ;)
		 */
		foreach ($array as $oKey => $oVal) {
			if ($key === $oKey || $val === $oVal) {
				$result[$oKey] = $oVal;
				break;
			}
		}
	}

	return $result;
}