SPL &reftitle.intro; The Standard PHP Library (SPL) is a collection of interfaces and classes that are meant to solve common problems. SPL provides a set of standard datastructure, a set of iterators to traverse over objects, a set of interfaces, a set of standard Exceptions, a number of classes to work with files and it provides a set of functions like spl_autoload_register &reference.spl.setup; &reference.spl.constants; &reference.spl.datastructures; &reference.spl.iterators; &reference.spl.interfaces; &reference.spl.exceptions; &reference.spl.reference; &reference.spl.files; &reference.spl.miscellaneous;