class_implements()
(PHP 5, PHP 7)
返回指定的类实现的所有接口。
说明
class_implements(mixed $class[,bool $autoload]): array
本函数返回一个数组,该数组中包含了指定类$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$autoload参数。 |
范例
class_implements() example
<?php interface foo { } class bar implements foo {} print_r(class_implements(new bar)); // since PHP 5.1.0 you may also specify the parameter as a string print_r(class_implements('bar')); function __autoload($class_name) { require_once $class_name . '.php'; } // use __autoload to load the 'not_loaded' class print_r(class_implements('not_loaded', true)); ?>
以上例程的输出类似于:
Array ( [foo] => foo ) Array ( [interface_of_not_loaded] => interface_of_not_loaded )
参见
class_parents()
返回指定类的父类。get_declared_interfaces()
返回一个数组包含所有已声明的接口
You can also check if a class implements an interface using instanceof. E.g. <?php if($myObj instanceof MyInterface) { echo "It is! It is!"; } ?>
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.
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.
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 )
The order of interfaces is not reliable and varies between PHP versions.