Returns the last "key" in the current Set

public function lastKey(): ?arraykey;

Since Sets do not have keys, it returns the last value.

This method is interchangeable with lastValue().


  • ?arraykey - The last value in the current Set, or null if the current Set is empty.


This example shows that lastKey returns the last value in the Set. An empty Set will return null as its last key/value.

$s = Set {'red', 'green', 'blue', 'yellow'};

$s = Set {};