Sum values from two objects where properties are the same

Question

How can I merge two objects and sum the values of matching properties? I am hoping for a built in function in PHP, otherwise I am seeking an easy way of doing it.

See code under, where I have $objectA and $objectB which I want to become $obj_merged.

$objectA = (object) [];
$objectA->a = 1;
$objectA->b = 1;
$objectA->d = 1;
  
$objectB = (object) [];
$objectB->a = 2;
$objectB->b = 2;
$objectB->d = 2;
  
$obj_merged = (object) [
    'a' => 3,
    'b' => 3,
    'd' => 3
];

Answer 1

What you want to achieve is a sum of the properties. A merge would overwrite the values. There is no built-in PHP function to do this with objects.

But you can use a simple helper function where you could put in as many objects as you like to sum up the public properties.

function sumObjects(...$objects): object
{
    $result = [];
    foreach($objects as $object) {
        foreach (get_object_vars($object) as $key => $value) {
            isset($result[$key]) ? $result[$key] += $value : $result[$key] = $value;
        }
    }
    return (object)$result;
}

$sumObject = sumObjects($objectA, $objectB);

stdClass Object
(
    [a] => 3
    [b] => 3
    [d] => 3
)