There are several PHP data structures

There are several types of data structures in PHP

There are 9 types of data structures in PHP. PHP has a very powerful SPL standard library, which provides It has a set of standard data structures, namely doubly linked list, stack, queue, heap, max heap, min heap, priority queue, array, and mapping.

Doubly linked list: SplDoublyLinkedList

Doubly linked list is an important linear storage structure. For each node in the doubly linked list, it not only stores its own information, but also To save the addresses of predecessor and successor nodes

Stack: SplStack

The stack is a special linear list because it can only be inserted or inserted at one end of the linear list Deleting elements (i.e. pushing and popping)

Queue: SplQueue

The SplQueue class provides the main functionality of a queue by using a doubly linked list.

Heap: SplHeap

Heap is a data structure designed to implement priority queues. It is constructed by constructing a binary heap (a type of binary tree). )accomplish.

Max Heap: SplMaxHeap

The SplMaxHeap class provides the main functionality of the heap, keeping the maximum value at the top.

Minimum Heap: SplMinHeap

The SplMinHeap class provides the main functionality of the heap, keeping the minimum value at the top.

Priority queue: SplPriorityQueue

SplPriorityQueue is implemented with a heap data structure. When we dequeue, we will take out the heap At this time, the characteristics of the heap are destroyed, and the heap will be adjusted accordingly to the stable state (MaxHeap or MinHeap), that is, the last element will be replaced at the top of the heap, and then the stable state verification will be performed. If it does not meet the characteristics of the heap, continue Adjust, or we will get a stable heap, so when the priorities are the same, the dequeuing order will not follow the enqueuing order.

Array: SplFixedArray

SplFixedArray is different from ordinary PHP Array. It is a fixed-length array with numbers as key names. It does not use hash (Hash) The storage method is closer to the C language array, so it is more efficient.

Mapping: SplObjectStorage

The SplObjectStorage class implements an object storage mapping table and is used in storage scenarios that require unique identification of multiple objects. .

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