is_a()

is_a() — Checks whether the object is of a given type or subtype.

Built-in function of PHP 8.5. The manual lists it as available in PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.

What it does

Determines if the given object_or_class is the class object type, or has class as one of its supertypes.

Signature

is_a(mixed $object_or_class, string $class, bool $allow_string = false): bool

Parameters

Parameter	Type	What it takes
$object_or_class	mixed	A class name or an object instance.
$class	string	The class or interface name
$allow_string	bool	If this parameter is set to false, a string class name as object_or_class is not allowed. This also prevents calling the autoloader if the class doesn't exist.

Return value

Returns true if object_or_class is the class object type, or has class as one of its supertypes, false otherwise.

Example

A runnable snippet:

// define a class class WidgetFactory { var $oink = 'moo'; } // create a new object $WF = new WidgetFactory(); if (is_a($WF, 'WidgetFactory')) { echo "yes, \$WF is still a WidgetFactory\n"; }