Question

I have a PHP Array, and I want to extract from it the duplicated values and keep the corresponding keys for each value, in a new Array.

This is my starting Array

Array
(
    [0] => ABC123-A
    [1] => BG231-B
    [2] => ABC123-A
    [3] => BG231-E
    [4] => BG231-F
    [5] => BG231-G
    [6] => BG231-H
    [7] => ABC123-A
    [8] => BG231-J
    [9] => BG231-K
    [10] => ABC123-A
)

And this is what I want to have:

Array
(
    [0] => ABC123-A
    [2] => ABC123-A
    [7] => ABC123-A
    [10] => ABC123-A
)

How can I do that ?

Thanks for help.

Answer 1

Test this out:

$return = array_unique($array);
var_dump(
    array_diff($array, array_diff($return, array_diff_assoc($array, $return)))
);