class_exists

Description

This function returns TRUE if the class given by class_name has been defined, FALSE otherwise.

Example 1. class_exists() example <?php // Check the class exists before trying to use it if (class_exists('MyClass')) {     $myclass = new MyClass(); } ?>

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

Example 2. autoload parameter example <?php function __autoload($class) {     include($class . '.php');     // Check to see if 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 interface_exists(), and get_declared_classes().