How to loop through field deltas of an object?
Entity reference fields have a method called referencedEntities().

Usage example:

$addresses = $entity-&gt;get('address');
foreach($addresses-&gt;referencedEntities() as $delta =&gt; $address) {
  // Do something with the $address entity
}


P.S.
If you only want the field then as @Clive mentioned you can just iterate over $addresses.