OOP : interface

Summary: in this tutorial, you will learn how to use PHP interface that is one of the most important building blocks in PHP object-oriented programming.

Introduction to PHP interface

An interface allows you to specify a list of methods that a class must implement. To define an interface, you use the interface keyword as follows:

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<?php interface IMyInterface{ // methods... }

An interface consists of methods that contain no implementation. In other words, all methods of the interface are abstract methods. An interface can have its own constants. See the following syntax:

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<?php interface IMyInterface{ const INTERFACE_CONSTANT_1 = 1; const INTERFACE_CONSTANT_2 = 'a string';   public function method_1(); public function method_2(); }

All the methods in the interface must have public visibility level.

http://www.zentut.com/php-tutorial/php-interface/