See Something Wrong? File an Issue
DocumentationHackReferenceClassHH\ImmMapfilter

HH\ImmMap::filter

Returns an ImmMap containing the values of the current ImmMap that meet a supplied condition

public function filter(
  (function(Tv): bool) $callback,
): ImmMap<Tk, Tv>;

Only values that meet a certain criteria are affected by a call to filter(), while all values are affected by a call to map().

The keys associated with the current ImmMap remain unchanged in the returned Map.

Guide

Parameters

  • (function(Tv): bool) $callback

Returns

  • ImmMap<Tk,Tv> - an ImmMap containing the values after a user-specified condition is applied.

Examples

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