SplHeap::compare

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

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

Description

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

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.

Parameters

value1: The value of the first node being compared.
value2: The value of the second node being compared.

Return Values

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.