Function for Checking Object Class Membership in OOP in PHP
is_aЗадание 1
Make a ChildClass class that inherits
from ParentClass. Create an object of the
ChildClass class, assign it to the variable
$obj.
Задание 2
Using the is_a function, check
if the object $obj belongs to the
ChildClass class.
Задание 3
Using the is_a function, check
if the object $obj belongs to the
ParentClass class.