How to merge all property values of two objects in PHP

Question

In PHP, how can I merge all the property values of two objects? I am hoping for a built in function in PHP, else if anyone can show me 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 = [
    'a' => 3,
    'b' => 3,
    'd' => 3
];

Does this answer your question? [What is the best method to merge two PHP objects?](https://stackoverflow.com/questions/455700/what-is-the-best-method-to-merge-two-php-objects) — Tangentially Perpendicular, Apr 04 '21 at 10:26
This is not really a "merge", more like a sum. What have you tried? Are the properties set in stone, or can they change? You can just loop over the object properties like you would an array's keys, if needed. This is pretty basic. — Jeto, Apr 04 '21 at 10:26

Markus Zeller · Accepted Answer · 2021-04-04T11:53:33.743

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
)

How to merge all property values of two objects in PHP

1 Answers1