Note:
In PHP 4.0.1pl2, 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 libraries you have compiled
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.