Abstract Class vs. Interface in PHP

1. Abstract Class in PHP
2. Interface in PHP
3. Abstract Class vs. Interface in PHP

This tutorial demonstrates the difference between abstract class and interface in PHP.

Before going into the differences, first, we must understand the concepts of abstract class and interface. Here are the important points for both abstract class and interface.

Abstract Class in PHP

The abstract class is partially implemented by developers and contains at least one abstract method, a method without any code. Here are some important points to understand the abstract class.

1. The abstract class is under partial abstraction.
2. We can create variables in the abstract class.
3. Abstract classes can contain abstract and non-abstract methods.
4. We can use any access modifier in the abstract class.
5. We can access the abstract class features from the derived class using the extends keyword.
6. In the abstract class, multiple inheritances are possible.

Here is an example of how to create an abstract class.

<?php
abstract class Demo_Abstract_Class {
    abstract protected
    function Get_Value();
    public
    function Print_Value() {
        print $this -> Get_Value();
    }
}
?>

Interface in PHP

The interface is defined by the interface keyword, where all the methods are abstract. Here are some important points to understand the interface.

1. Interface is under full abstraction.
2. We cannot create variables in the interface.
3. The interface only contains abstract methods.
4. Only the public access modifier is used in the interface.
5. We can get the interface from a derived class using the implement keyword.
6. Multiple inheritances are possible with interfaces.

Here is an example to demonstrate the interface.

<?php
interface Demo_Interface {
    public
    function execute();
}
?>

Abstract Class vs. Interface in PHP

Here are the differences between abstract class and interface.