useful recursive PHP functions

recursively ...

PHP has a single type operator: instanceof. instanceof is used to determine whether a given object is of a specified object class.

instanceof was introduced in PHP 5.

<?php
class A { }
class B { }

$thing = new A;

if ($thing instanceof A) {
    echo 'A';
}
if ($thing instanceof B) {
    echo 'B';
}
?>

As $thing is an object of type A, but not B, only the block dependent on the A type will be executed: