class_exists
class_exists
(PHP 4, PHP 5, PHP 7)
class_exists — Checks if the class has been defined
Description
bool class_exists ( string $class_name [, bool $autoload = true ] )
This function checks whether or not the given class has been defined.
Parameters
-
class_name
-
The class name. The name is matched in a case-insensitive manner.
-
autoload
-
Whether or not to call __autoload by default.
Return Values
Returns TRUE
if class_name
is a defined class, FALSE
otherwise.
Changelog
Version | Description |
---|---|
5.0.2 | No longer returns TRUE for defined interfaces. Use interface_exists(). |
Examples
Example #1 class_exists() example
<?php // Check that the class exists before trying to use it if (class_exists('MyClass')) { $myclass = new MyClass(); } ?>
Example #2 autoload
parameter example
<?php function __autoload($class) { include($class . '.php'); // Check to see whether the include declared the class if (!class_exists($class, false)) { trigger_error("Unable to load class: $class", E_USER_WARNING); } } if (class_exists('MyClass')) { $myclass = new MyClass(); } ?>
See Also
- function_exists() - Return TRUE if the given function has been defined
- interface_exists() - Checks if the interface has been defined
- get_declared_classes() - Returns an array with the name of the defined classes
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Licensed under the Creative Commons Attribution License v3.0 or later.
https://secure.php.net/manual/en/function.class-exists.php