SplHeap::extract

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

SplHeap::extractExtracts 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
?>