SplHeap::extract

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

SplHeap::extract — Extracts a node from top of the heap and sift up

说明

public SplHeap::extract ( ) : mixed

参数

此函数没有参数。

返回值

The value of the extracted node.

错误／异常

Throws RuntimeException when the data-structure is empty.

User Contributed Notes

Sandro Alves Peres 12-Jun-2013 01:06


<?php

$heap = new SplMaxHeap(); # Ascending order

$heap->insert('E');

$heap->insert('B');

$heap->insert('D');

$heap->insert('A');

$heap->insert('C');



echo $heap->extract(), PHP_EOL; # E

echo $heap->extract(), PHP_EOL; # D



$heap = new SplMinHeap(); # Descending order

$heap->insert('E');

$heap->insert('B');

$heap->insert('D');

$heap->insert('A');

$heap->insert('C');



print PHP_EOL;

echo $heap->extract(), PHP_EOL; # A

echo $heap->extract(), PHP_EOL; # B

?>