Group rows of 2d array by one column and sum another column

Question

I have an array:

Array 
(
[0] => Array
    (
        [setid] => 2
        [income] => 100
    )

[1] => Array
    (
        [setid] => 2
        [income] => 120
    )

[2] => Array
    (
        [setid] => 3
        [income] => 700
    )
)

I need to find entries with the same setid, sum their income up and delete duplicate entrys - in the end it should look like this:

Array
(
[0] => Array
    (
        [setid] => 2
        [income] => 220
    )

[1] => Array
    (
        [setid] => 3
        [income] => 700
    )
)

Does someone know a sophisticated solution for my problem or do I have to take the long road and do every step manually?

Answer 1

Just create a new array which you make fast adressable by using the setid as key. And reindex the array at the end.

$result = array();
foreach ($array as $val) {
    if (!isset($result[$val['setid']]))
        $result[$val['setid']] = $val;
    else
        $result[$val['setid']]['income'] += $val['income'];
}
$result = array_values($result); // reindex array