array unique removing key

<?php
$fruits_list = array('Orange',  'Apple', ' Banana', 'Cherry', ' Banana');
$result = array_unique($fruits_list);
print_r($result);
?>
  
Output:

Array ( [0] => Orange [1] => Apple [2] => Banana [3] => Cherry ) $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 )