SplHeap::compare

(PHP 5 >= 5.3.0, PHP 7)

SplHeap::compare — Compare elements in order to place them correctly in the heap while sifting up

说明

abstract protected SplHeap::compare ( mixed $value1 , mixed $value2 ) : int

Compare value1 with value2.

警告

Throwing exceptions in SplHeap::compare() can corrupt the Heap and place it in a blocked state. You can unblock it by calling SplHeap::recoverFromCorruption(). However, some elements might not be placed correctly and it may hence break the heap-property.

参数

value1

The value of the first node being compared.

value2

The value of the second node being compared.

返回值

Result of the comparison, positive integer if value1 is greater than value2, 0 if they are equal, negative integer otherwise.

注意:

Having multiple elements with the same value in a Heap is not recommended. They will end up in an arbitrary relative position.