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 — Checks if the interface has been defined
Opis
bool interface_exists
( string
$interface_name
[, bool $autoload = true
] )Checks if the given interface has been defined.
Zwracane wartości
Returns TRUE if the interface given by
interface_name has been defined, FALSE otherwise.
Przykłady
Przykład #1 interface_exists() example
<?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 12:35
andrey at php dot net
23-Oct-2004 10:40
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.
