Type Operators

PHP has a single type operator: instanceof is used to determine whether a given object, his parents or their implemented interfaces are of a specified object class.

The instanceof operator was introduced in PHP 5. Before this time is_a() was used but is_a() has since been deprecated in favor of instanceof.


<?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:

See also get_class() and is_a().