Question

I am looking for a function, if any, to preserve or merge values into similar key, but no luck so far.

array_combine simply removes the value:

array_combine(array('a','a','b'), array(1,2,3));

Returns:

Array
(
    [a] => 2
    [b] => 3
)

Expected:

Array
(
    [a] => 1,2
    [b] => 3
)

Any hint is very much appreciated.

Thanks

UPDATE: I didn’t know, and didn’t articulate better about the merged values (1,2), but then I had better accepted Jeroen array of values for easier breakdowns of possible array of values.
Thanks to everyone who has kindly helped.

Answer 1

This:

function array_combine_custom($arr1, $arr2) {
    $out = array();

    $arr1 = array_values($arr1);
    $arr2 = array_values($arr2);

    foreach($arr1 as $key1 => $value1) {
        $out[(string)$value1] [] = $arr2[$key1];
    }

    return $out;
}

Returns:

Array
(
    [a] => Array
        (
            [0] => 1
            [1] => 2
        )

    [b] => Array
        (
            [0] => 3
        )

)