Php Inheritance

Php Inheritance

Php Inheritance :

1.      Inheritance is the process of creating a new concept from an already existing concept(s);

2.      Inheritance is introduced for reusability.

Types of inheritance:

Simple inheritance :

Herarchiel Inheritance:

Multi Level Inheritance :

Multiple Inheritance :

Hybrid Inheritance :

=(2) + (3) + (4) 

The newly created class is known as “sub-class” and the class from which it is created is known as parent class.

“extends” is the keyword used for creating a subclass.

Class B extends A

{

}

After “extends” keyword we can give only one class name thet means in php we cannot create a class from morethan one parent class in order to overcome ambiguity error .multiple inheritance is happening through inheritance.

<?php

class A

{

    public $a=10,$b=20;

    function addNum($x=0,$y=0)

    {

      $res = $x + $y;

      echo "sum=".$res."<br>";

     

    }

}

?>

<?php

class B extends A

{

    public $c=30,$d=40;

    function subNum($x=0,$y=0){

        $res=$x-$y;

        echo "difference=".$res."<br>";

        

    }

}

?>

<?php

echo "<h1>";

$obj = new B();

echo $obj->a."--".$obj->d."<br>";

$obj->addNum(11,22);

$obj->subNum(22,9);

?>

OutPut:

10--40

sum=33

difference=13