Magento 2 - Multiple categories filter on product collection

Question

I have a product collection $collection which is created by Magento\Catalog\Model\ResourceModel\Product\Collection

code is:

$collection = $objectManager->create('Magento\Catalog\Model\ResourceModel\Product\Collection');
$collection->addAttributeToSelect('*');
$collection->addAttributeToFilter('status', array('eq' => \Magento\Catalog\Model\Product\Attribute\Source\Status::STATUS_ENABLED));

How can I add multiple category filter in it?

Answer 1

First of all, do not use object manager, create your object from constructor

$protected $collection;

public function __construct(
    ...
    \Magento\Catalog\Model\ResourceModel\Product\Collection $collection
    ...
)
{
    ...
    $this->collection = $collection;
    ...
}

For your category filter use this:

$categories = [12,13,14]; //Category ids in array
$collection->addCategoriesFilter(array('in' => $categories));

Collection will join category table and will add your filter