SplHeap::extract()
(PHP 5 >= 5.3.0, PHP 7)
Extracts a node from top of the heap and sift up
说明
public SplHeap::extract(void) : 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.
<?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 ?>