Php/docs/function.class-exists
class_exists
(PHP 4, PHP 5, PHP 7)
class_exists — Checks if the class has been defined
Description
class_exists
( string $class_name
[, bool $autoload = TRUE
] ) : bool
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.
Examples
Example #1 class_exists() example
<?php// Check that the class exists before trying to use itif (class_exists('MyClass')) { $myclass = new MyClass();}?>
Example #2 autoload parameter example
<?phpfunction __autoload($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
