HH\ImmSet::map

Returns an ImmSet containing the values after an operation has been applied to each value in the current ImmSet

public function map<Tu as arraykey>(
  (function(Tv): Tu) $callback,
): ImmSet<Tu>;

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

Guide

• Examples

Parameters

• (function(Tv): Tu) $callback

Returns

• ImmSet<Tu> - a ImmSet containing the values after a user-specified operation is applied.

Examples

See [Set::map](</hack/reference/class/Set/map/#examples>) for usage examples.