class_implements

    (PHP 5, PHP 7, PHP 8)

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

    Description

    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.

    Parameters

    object_or_class

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

    autoload

    Whether to autoload if not already loaded.

    Return Values

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

    Examples

    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));

    ?>

    The above example will output something similar to:

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

    Notes

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

    See Also

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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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