Question

I have an array of objects containing a partId and a quantity. I want for each partId in the final array to be unique, by summing the quantity of objects with the same partId.

I want this:

Array
(
    [0] => stdClass Object
        (
            [partId] => 232032
            [quantity] => 2
        )

    [1] => stdClass Object
        (
            [partId] => 232032
            [quantity] => 1
        )

    [2] => stdClass Object
        (
            [partId] => 232031
            [quantity] => 1
        )
)

To end up like this:

Array
(
    [0] => stdClass Object
        (
            [partId] => 232032
            [quantity] => 3
        )

    [1] => stdClass Object
        (
            [partId] => 232031
            [quantity] => 1
        )
)

---

Here’s what I’m doing now, I feel like there has to be a better way.

$tmp = array();
foreach ($array1 as $item) {
    if (array_key_exists($item->partId, $tmp)) {
        $tmp[$item->partId]->quantity += $item->quantity;
    } else {
        $tmp[$item->partId] = $item;
    }
}
$array2 = array_merge($tmp);

Answer 1

You are almost there:

$tmp = array();
foreach ($array1 as $key => $item) {
    if (array_key_exists($item->partId, $tmp)) {
        $array1[$tmp[$item->partId]]->quantity += $item->quantity;
        unset($array1[$key]);
    } else {
        $tmp[$item->partId] = $key;
    }
}

print_r($array1);