This section lists standard predefined classes. Miscellaneous extensions define other classes which are described in their reference.
These classes are defined in the standard set of functions included in the PHP build.
These additional predefined classes were introduced in PHP 5.0.0.
The predefined final class Closure was introduced in PHP 5.3.0. It is used for internal implementation of anonymous functions.
The class has a constructor forbidding the manual creation of the object (issues E_RECOVERABLE_ERROR) and the __invoke method with the calling magic.