I\'m looking at the PHP Manual, and I\'m not seeing a section on data structures that most languages have, such as lists and sets. Am I just blind or does PHP not have anything
PHP offers data structures through the Standard PHP Library (SPL) basic extension, which is available and compiled by default in PHP 5.0.0.
The data structures offered are available with PHP 5 >= 5.3.0, and includes:
A Doubly Linked List (DLL) is a list of nodes linked in both directions to each others. Iterator’s operations, access to both ends, addition or removal of nodes have a cost of O(1) when the underlying structure is a DLL. It hence provides a decent implementation for stacks and queues.
Heaps are tree-like structures that follow the heap-property: each node is greater than or equal to its children, when compared using the implemented compare method which is global to the heap.
Arrays are structures that store the data in a continuous way, accessible via indexes. Don’t confuse them with PHP arrays: PHP arrays are in fact implemented as ordered hashtables.
A map is a datastructure holding key-value pairs. PHP arrays can be seen as maps from integers/strings to values. SPL provides a map from objects to data. This map can also be used as an object set.
Source: http://php.net/manual/en/spl.datastructures.php