Translations:Developers/Object oriented programming in PHP/Abstract classes and interfaces/18/en


 * An interface can extend multiple interfaces whereas (abstract) classes can only extend one class.
 * All methods of an interface have to be public where abstract methods can be either public or protected, but not private.
 * When an interface is added as parameter type in a method of an interface, then all objects are accepted, which implement the given interface directly or indirectly.