SplHeap::compare

(PHP 5 >= 5.3.0)

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

说明

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

Compare value1 with value2.

Warning

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.

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