A brief introduction to abstract methods and abstract classes and interfaces in PHP

This article brings the content is about PHP abstract methods and abstract class and interface of the simple introduction, there is a certain reference value, the need for friends can refer to, I hope to help you.

Abstract methods

abstract function say ();

Abstract class

Abstract class person{    abstract function Say ();}

1. Abstract classes cannot be instantiated

2. Abstract classes can have abstract methods

3. Subclasses must implement abstract methods

Interface

1. The methods in the interface are all abstract methods

2. The interface attribute must be a constant

3. Must be public

4.interface Declaration

Interface demo{    const name= ' NGYHD ';    function test ();}