A little note on namespaces that may be obvious to some, but was not obvious to me.
Although you can make the below statement when the statement is in the same namespace as the interface/class declaration MyInterface...
<?php
$foo instanceof MyInterface
?>
Making use of the interface_exists, or class_exists functions, you must enter the full namespaced interface name like so (even if the function call is from the same namespace.)
<?php
interface_exists(__NAMESPACE__ . '\MyInterface', false);
?>
interface_exists
(PHP 5 >= 5.0.2)
interface_exists — Checa se a interface foi definida
Descrição
bool interface_exists
( string $interface_name
[, bool $autoload
] )
Verifica se uma interface foi definida.
Valor Retornado
Essa função retorna TRUE se a interface de nome interface_name já foi definida, FALSE caso contrário.
Exemplos
Exemplo #1 Exemplo de uso de interface_exists()
<?php
// Check the interface exists before trying to use it
if (interface_exists('MyInterface')) {
class MyClass implements MyInterface
{
// Methods
}
}
?>
nils dot rocine at gmail dot com
26-Oct-2011 06:35
andrey at php dot net
24-Oct-2004 04:40
As far as I remember interface_exists() was added in 5.0.2 . In 5.0.0 and 5.0.1 class_exists() used to return TRUE when asked for a existing interface. Starting 5.0.2 class_exists() doesn't do that anymore.
