array intersect for object array php

Question

I want to know how to array_intersect for object array.

Answer 1

You can use array_uintersect in conjunction with spl_object_hash, see an example:

    array_uintersect($a, $b, function($a, $b) {
        return strcmp(spl_object_hash($a), spl_object_hash($b));
    });

where '$a' and '$b' are arrays of some objects that you want to intersect.

Answer 2

Just for completeness: Implement __toString() method in your object returning a unique value. For database entities this might be as easy as returning the fully qualified class name postfixed with the ID of the record. But it can also be arbitrarily complex by doing some hashing or even worse things.

In my opinion, it's the class's duty to serialize itself or create something unique to compare its objects by. Using anything outside of a class to serialize an object might result in strange behaviour (including comparing objects of different classes, which must never result in equality).