PHP Function Reference

PHP interface_exists() Function



The PHP interface_exists() function is used to check whether or not the given interface has been defined. It returns true if the given interface is defined, else returns false.

Syntax

interface_exists(interface, autoload)

Parameters

interface Required. Specify the interface name to check. The name is matched in a case-insensitive manner.
autoload Optional. Specify whether to call __autoload or not by default.

Return Value

Returns true if interface is a defined interface, false otherwise.

Example: interface_exists() example

The example below shows the usage of interface_exists() function.

<?php
//checking that the interface exists 
//before trying to use it
if (interface_exists('MyInterface')) {
    class MyClass implements MyInterface {
      // Methods
    }
  echo "A class using 'MyInterface' is created.";
} else {
  echo "'MyInterface' do not exist!.";
}
?>

The output of the above code will be:

'MyInterface' do not exist!.

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