PHP Conference Nagoya 2025

class_implements

(PHP 5, PHP 7, PHP 8)

class_implements Return the interfaces which are implemented by the given class or interface

Descrizione

class_implements(object|string $object_or_class, bool $autoload = true): array|false

This function returns an array with the names of the interfaces that the given object_or_class and its parents implement.

Elenco dei parametri

object_or_class

An object (class instance) or a string (class or interface name).

autoload

Whether to autoload if not already loaded.

Valori restituiti

An array on success, or false when the given class doesn't exist.

Esempi

Example #1 class_implements() example

<?php

interface foo { }
class
bar implements foo {}

print_r(class_implements(new bar));

// you may also specify the parameter as a string
print_r(class_implements('bar'));

spl_autoload_register();

// use autoloading to load the 'not_loaded' class
print_r(class_implements('not_loaded', true));

?>

Il precedente esempio visualizzerà qualcosa simile a:

Array
(
    [foo] => foo
)
Array
(
    [foo] => foo
)
Array
(
    [interface_of_not_loaded] => interface_of_not_loaded
)

Note

Nota: To check that an object implements an interface, instanceof or the is_a() function should be used instead.

Vedere anche:

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User Contributed Notes 3 notes

up
16
ludvig dot ericson at gmail dot nospam dot com
19 years ago
Hint:
<?php
in_array
("your-interface", class_implements($object_or_class_name));
?>
would check if 'your-interface' is ONE of the implemented interfaces.
Note that you can use something similar to be sure the class only implements that, (whyever you would want that?)
<?php
array("your-interface") == class_implements($object_or_class_name);
?>

I use the first technique to check if a module has the correct interface implemented, or else it throws an exception.
up
10
a dot panek at brainsware dot org
11 years ago
Calling class_implements with a non-loadable class name or a non-object results in a warning:

<?php
// Warning: class_implements(): Class abc does not exist and could not be loaded in /home/a.panek/Projects/sauce/lib/Sauce/functions.php on line 196

$interfaces = class_implements('abc');
?>

This is not documented and should just return FALSE as the documentation above says.
up
3
trollll23 at yahoo dot com
19 years ago
Luckily, it prints out superinterfaces as well in reverse order so iterative searching works fine:

<?php

interface InterfaceA { }

interface
InterfaceB extends InterfaceA { }

class
MyClass implements InterfaceB { }

print_r(class_implements(new MyClass()));

?>

prints out:

Array
(
[InterfaceB] => InterfaceB
[InterfaceA] => InterfaceA
)
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