PHP Manual: interface

interface_exists

(PHP 5 >= 5.0.2)

interface_exists -- Checks if the interface has been defined

Description

bool interface_exists ( string interface_name [, bool autoload] )

This function returns TRUE if the interface given by interface_name has been defined, FALSE otherwise.

Example 1. interface_exists() example

<?php
// Check the interface exists before trying to use it
if (interface_exists('MyInterface')) {
    class MyClass implements MyInterface
    {
        // Methods
    }
}

?>

interface_exists() will attempt to call __autoload by default, if you don't want interface_exists() to call __autoload, you can set the parameter autoload to FALSE.