Returns an array of the names of the declared classes in the current script.
Note: In PHP 4.0.1, three extra classes are returned at the beginning of the array: stdClass (defined in Zend/zend.c), OverloadedTestClass (defined in ext/standard/basic_functions.c) and Directory (defined in ext/standard/dir.c).
Also note that depending on what extensions you have compiled or loaded into PHP, additional classes could be present. This means that you will not be able to define your own classes using these names. There is a list of predefined classes in the Predefined Classes section of the appendices.