Abstract Classes

Abstract classes are like normal classes for use. But they can not be sampled as classes. That's why you call abstract. Abstract classes can be thought of as a combination of an interface and a class. Object inheritance is very successful in common object use and prototyping. They are often used to create a common object to class clusters doing similar work and to ensure that these classes conform to a particular structure. When abstract class definition is done , abstract is used before class statement .

For a better understanding of abstract classes, review the following comparison chart;

# Syntax

The syntax of abstract classes is analogous to the syntax of classes and interfaces, but with   an abstract expression per class statement .

<?php abstract class ExampleClassAbstract
{
    # Abstract yöntemler public görünürlüğe sahip ve gövdesiz olmalıdır.
    # Arayüz kullanımına benzer.
    # Alt sınıf aynı yöntemi içermesi için zorlar.
    abstract public function exampleFunction();

    # Ortak yöntemler gövdeli olur.
    # Nesne kalıtımına benzer.
    # Alt sınıflar için ortak yöntem oluşturur.
    public function commonFunction()
    {
        return 'Common Function';
    }
}

# Create Abstract Class

We have created Vechile :: class as an abstract class.

<?php abstract class Vehicle
{
    protected $color = 'White';
 
    abstract public function wayType();

    public function setColor(string $color)
    {
        $this->color = $color;
    }

    public function getColor() : string
    {
        return $this->color;
    }
}

We have forced the above abstract class to have the wayType () method of inheriting subclasses . Note that a method that has an abstract expression must have public visibility and no body.