What's the fastest way to compare two objects in PHP?

Question

Let\'s say I have an object - a User object in this case - and I\'d like to be able to track changes to with a separate class. The User object should not have to change it\'s be

Answer 1

Here is a piece of code that supports private properties:

$reflection_1 = new \ReflectionClass($object_1);
$reflection_2 = new \ReflectionClass($object_2);

$props_1 = $reflection_1->getProperties();

foreach ($props_1 as $prop_1) {

    $prop_1->setAccessible(true);
    $value_1 = $prop_1->getValue($object_1);

    $prop_2 = $reflection_2->getProperty($prop_1->getName());

    $prop_2->setAccessible(true);
    $value_2 = $prop_2->getValue($object_2);

    if ($value_1 === $value_2) {
        // ...
    } else {
        // ...
    }
}

Note that if $object_1 has properties that $object_2 doesn't have, the above code will produce errors when trying to access them.

For such a case, you would need first to intersect $reflection_1->getProperties() with $reflection_2->getProperties().