array_unique for objects?

php arrays methods
Johannes picture Johannes · Mar 11, 2010 · Viewed 88k times · Source

Is there any method like the array_unique for objects? I have a bunch of arrays with 'Role' objects that I merge, and then I want to take out the duplicates :)

Answer

Matthieu Napoli picture Matthieu Napoli · Aug 13, 2013

array_unique works with an array of objects using SORT_REGULAR:

class MyClass {
    public $prop;
}

$foo = new MyClass();
$foo->prop = 'test1';

$bar = $foo;

$bam = new MyClass();
$bam->prop = 'test2';

$test = array($foo, $bar, $bam);

print_r(array_unique($test, SORT_REGULAR));

Will print:

Array (
    [0] => MyClass Object
        (
            [prop] => test1
        )

    [2] => MyClass Object
        (
            [prop] => test2
        )
)

See it in action here: http://3v4l.org/VvonH#v529

Warning: it will use the "==" comparison, not the strict comparison ("===").

So if you want to remove duplicates inside an array of objects, beware that it will compare each object properties, not compare object identity (instance).

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