[Solved] How to use recursion to sum specific values in a multidimensional array?

by


Recursion doesn’t seem to be necessary for the “parent” direct values, so that can be done with a direct foreach loop.

The “children” indirect values require recursion. I’ve elected to use array_walk_recursive() to access every “leaf node” in the array. This will also store the parents’ indirect values too, so I subtract those values after array_walk_recursive() is finished.

Code: (Demo)

$result['sum_direct'] = 0;
$result['sum_indirect'] = 0;
$parents_indirect = 0;
echo "<pre>";
$array = json_decode($json, true)['users'];
foreach ($array as $users) {
    $result['sum_direct'] += $users['package'][1]['direct'];
    $parents_indirect += $users['package'][2]['indirect'];
}
array_walk_recursive($array, function ($v, $k) use (&$result) {
        if ($k === 'indirect') {
            $result['sum_indirect'] += $v;
        }
    });
$result['sum_indirect'] -= $parents_indirect;

echo json_encode($result);

Output using your in-question data:

{"sum_direct":400,"sum_indirect":3000}

Output using your full json from github:

{"sum_direct":600,"sum_indirect":22400}

10

solved How to use recursion to sum specific values in a multidimensional array?