How to merge two php Doctrine 2 ArrayCollection()

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!

Solution 1:

Better (and working) variant for me:

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

Solution 2:

You can simply do:

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

Solution 3:

If you are required to prevent any duplicates, this snippet might help. It uses a variadic function parameter for usage with PHP5.6.

/**
 * @param array... $arrayCollections
 * @return ArrayCollection
 */
public function merge(...$arrayCollections)
{
    $returnCollection = new ArrayCollection();

    /**
     * @var ArrayCollection $arrayCollection
     */
    foreach ($arrayCollections as $arrayCollection) {
        if ($returnCollection->count() === 0) {
            $returnCollection = $arrayCollection;
        } else {
            $arrayCollection->map(function ($element) use (&$returnCollection) {
                if (!$returnCollection->contains($element)) {
                    $returnCollection->add($element);
                }
            });
        }
    }

    return $returnCollection;
}

Might be handy in some cases.

Solution 4:

$newCollection = new ArrayCollection((array)$collection1->toArray() + $collection2->toArray()); 

This should be faster than array_merge. Duplicate key names from $collection1 are kept when same key name is present in $collection2. No matter what the actual value is