numbers not repeated in array in php code example

Example 1: get duplicate value from array php

$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 )

Example 2: php check for duplicates in array

function has_dupes($array) {
    $dupe_array = array();
    foreach ($array as $val) {
        if (++$dupe_array[$val] > 1) {
            return true;
        }
    }
    return false;
}