ABSTRACT CLASS

An abstract class is a mix between an interface and a class. It can be define functionality as well as interface.

Classes extending an abstract class must implement all of the abstract methods defined in the abstract class.
An abstract class is declared the same way as classes with the addition of the 'abstract' keyword.

SYNTAX:

abstract class MyAbstract
{
	//Methods
}
//And is attached to a class using the extends keyword.
class Myclass extends MyAbstract
{
	//class methods
}

Example 1

<?php
abstract class a
{
abstract public function dis1();
abstract public function dis2();
}
class b extends a
{
public function dis1()
	{
		echo "javatpoint";
	}
	public function dis2()
	{
		echo "SSSIT";	
	}
}
$obj = new b();
$obj->dis1();
$obj->dis2();
?>

Output:

Example 2

<?php
abstract class Animal
{
    public $name;
    public $age;
public function Describe()
    	{
        		return $this->name . ", " . $this->age . " years old";    
    	}
abstract public function Greet();
   	}
class Dog extends Animal
{
public function Greet()
    	{
        		return "Woof!";    
    	}
    
    	public function Describe()
    	{
        		return parent::Describe() . ", and I'm a dog!";    
    	}
}
$animal = new Dog();
$animal->name = "Bob";
$animal->age = 7;
echo $animal->Describe();
echo $animal->Greet();
?>

Output: