<?php

function findRepeats($array){
	return array_filter(array_count_values($array), function($item) {
		if($item > 1){
			return $item;
		}
	});
}

$a = [0,1,2,3,4,5,5,5,6,6,7,8];
foreach(findRepeats($a) as $key => $value){
	echo 'The "'.$key.'" element is repeated '.$value.' times in array <br>';
}