HH\Set::mapWithKey

Returns a Set containing the values after an operation has been applied to each "key" and value in the current Set.

Description

public function mapWithKey(
  callable $callback,
): Set<Tu>

Returns a Set containing the values after an operation has been applied to each "key" and value in the current Set.

Since Sets don't have keys, the callback uses the values as the keys as well.

Every value in the current Set is affected by a call to mapWithKey(), unlike filterWithKey() where only values that meet a certain criteria are affected.

Parameters

  • callable $callback - The callback containing the operation to apply to the current Set keys and values.

Return Values

  • Set<Tu> - a Set containing the values after a user-specified operation on the current Set's values is applied.