数据结构
Table of Contents
- SplDoublyLinkedList
- SplStack
- SplQueue
- SplHeap
- SplMaxHeap
- SplMinHeap
- SplPriorityQueue
- SplFixedArray
- SplObjectStorage
SPL提供了一组标准数据结构. They are grouped here by their underlying implementation which usually defines their general field of application.
双向链表
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.
- SplDoublyLinkedList
- SplStack
- SplQueue
堆
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.
- SplHeap
- SplMaxHeap
- SplMinHeap
- SplPriorityQueue
阵列
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.
- SplFixedArray
映射
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.
- SplObjectStorage