PHP is developed and maintained by a global community of contributors.
The PHP Foundation helps fund this work. If PHP is part of your business or projects, consider sponsoring the Foundation.
本节列出标准的预定义类。各种扩展库定义了其它类，其说明在各自的参考文档中。
这些类由一些内建在 PHP 中的标准函数定义。
