$arr = array(1, 4, 6, 1, 8, 9, 4, 6);
$unique = array_unique($arr);
$duplicates = array_diff_assoc($arr, $unique);
print_r($duplicates);
Array ( [3] => 1 [6] => 4 [7] => 6 )
$counts = array_count_values($array);
$duplicate_title = array_filter($array, function ($value) use ($counts) {
return $counts[$value] > 1;
});
if (count($array) === count(array_unique($array))) {
//values are unique
}
function has_dupes($array) {
$dupe_array = array();
foreach ($array as $val) {
if (++$dupe_array[$val] > 1) {
return true;
}
}
return false;
}