The SplPriorityQueue class

Introduction

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

The SplPriorityQueue class provides the main functionalities of a prioritized queue, implemented using a max heap.

Note: The order of elements with identical priority is undefined. It may differ from the order in which they have been inserted.

Class synopsis

public compare(mixed $priority1, mixed $priority2): int

public count(): int

public current(): mixed

public extract(): mixed

public getExtractFlags(): int

public insert(mixed $value, mixed $priority): bool

public isCorrupted(): bool

public isEmpty(): bool

public key(): int

public next(): void

public recoverFromCorruption(): bool

public rewind(): void

public setExtractFlags(int $flags): int

public top(): mixed

public valid(): bool

Table of Contents

• SplPriorityQueue::compare — Compare priorities in order to place elements correctly in the heap while sifting up
• SplPriorityQueue::__construct — Constructs a new empty queue
• SplPriorityQueue::count — Counts the number of elements in the queue
• SplPriorityQueue::current — Return current node pointed by the iterator
• SplPriorityQueue::extract — Extracts a node from top of the heap and sift up
• SplPriorityQueue::getExtractFlags — Get the flags of extraction
• SplPriorityQueue::insert — Inserts an element in the queue by sifting it up
• SplPriorityQueue::isCorrupted — Tells if the priority queue is in a corrupted state
• SplPriorityQueue::isEmpty — Checks whether the queue is empty
• SplPriorityQueue::key — Return current node index
• SplPriorityQueue::next — Move to the next node
• SplPriorityQueue::recoverFromCorruption — Recover from the corrupted state and allow further actions on the queue
• SplPriorityQueue::rewind — Rewind iterator back to the start (no-op)
• SplPriorityQueue::setExtractFlags — Sets the mode of extraction
• SplPriorityQueue::top — Peeks at the node from the top of the queue
• SplPriorityQueue::valid — Check whether the queue contains more nodes