How to merge two php Doctrine 2 ArrayCollection()

Question

Is there any convenience method that allows me to concatenate two Doctrine ArrayCollection()? something like:

$collection1 = new ArrayCollection();
$collection2 = new ArrayCollection();

$collection1->add($obj1);
$collection1->add($obj2);
$collection1->add($obj3);

$collection2->add($obj4);
$collection2->add($obj5);
$collection2->add($obj6);

$collection1->concat($collection2);

// $collection1 now contains {$obj1, $obj2, $obj3, $obj4, $obj5, $obj6 }

I just want to know if I can save me iterating over the 2nd collection and adding each element one by one to the 1st collection.

Thanks!

Answer 1

Better (and working) variant for me:

$collection3 = new ArrayCollection(
    array_merge($collection1->toArray(), $collection2->toArray())
);

Answer 2

You can simply do:

$a = new ArrayCollection();
$b = new ArrayCollection();
...
$c = new ArrayCollection(array_merge((array) $a, (array) $b));