class_implements

(PHP 5 >= 5.1.0)

class_implements — 返回指定的类实现的所有接口。

说明

array class_implements ( mixed $class [, bool $autoload ] )

本函数返回一个数组，该数组中包含了指定类class及其父类所实现的所有接口的名称。

参数

class: 对象（类实例）或字符串（类名称）。
autoload: 是否允许使用__autoload 魔术函数来自动装载该类。默认值为 TRUE 。

返回值

调用成功则返回一个数组，否则返回 FALSE 。

更新日志

版本	说明
5.1.0	增加了允许参数`class`为字符串的选项。增加了`autoload`参数。

范例

Example #1 class_implements() example

  <?php

 interface  foo  { }
class  bar  implements  foo  {}

 print_r ( class_implements (new  bar ));

 // since PHP 5.1.0 you may also specify the parameter as a string
 print_r ( class_implements ( 'bar' ));


function  __autoload ( $class_name ) {
   require_once  $class_name  .  '.php' ;
}

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

 ?>

以上例程的输出类似于：

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

参见

class_parents() - 返回指定类的父类。
get_declared_interfaces() - 返回一个数组包含所有已声明的接口

用户评论:

[#1] a dot panek at brainsware dot org [2013-11-05 13:29:28]

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.

[#2] paul at paulferrett dot com [2009-12-30 17:35:08]

You can also check if a class implements an interface using instanceof.

E.g.
<?php if($myObj instanceof MyInterface) { echo "It is! It is!"; } ?>

[#3] trollll23 at yahoo dot com [2005-10-25 12:57:08]

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
    )

[#4] ludvig dot ericson at gmail dot nospam dot com [2005-08-01 12:41:55]

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.