HH\Set::lastKey

Returns the last "key" in the current Set.

Description

public function lastKey(): mixed

Returns the last "key" in the current Set.

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

This method is interchangeable with lastValue().

Return Values

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

Examples

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

<?hh

namespace Hack\UserDocumentation\API\Examples\Set\LastKey;

$s = Set {'red', 'green', 'blue', 'yellow'};
var_dump($s->lastKey());

$s = Set {};
var_dump($s->lastKey());
Output
string(6) "yellow"
NULL