You can also check if a class implements an interface using instanceof.
E.g.
<?php
if($myObj instanceof MyInterface) {
echo "It is! It is!";
}
?>
(PHP 5, PHP 7, PHP 8)
class_implements — Retorna as interfaces que são implementadas pela classe
Esta função retorna um array com os nomes das interfaces que a
classe class
e seus pais implementam.
class
Um objeto (instância da classe) ou uma string (nome da classe).
autoload
Permitir ou não que essa função carregue a classe automaticamente pelo
método mágico __autoload
O padrão é true
.
Um array em sucesso, ou false
em caso de erro.
Versão | Descrição |
---|---|
5.1.0 |
Adicionada a opção de passar o parâmetro class como
uma string. Adicionado o parâmetro autoload .
|
Exemplo #1 Exemplo de class_implements()
<?php
interface foo { }
class bar implements foo {}
print_r(class_implements(new bar));
// desde o PHP 5.1.0 você também pode especificar o parâmetro como uma string
print_r(class_implements('bar'));
function __autoload($class_name) {
require_once $class_name . '.php';
}
// utiliza o __autoload para carregar a classe 'not_loaded'
print_r(class_implements('not_loaded', true));
?>
O exemplo acima irá imprimir algo similar à:
Array ( [foo] => foo ) Array ( [interface_of_not_loaded] => interface_of_not_loaded )
You can also check if a class implements an interface using instanceof.
E.g.
<?php
if($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.