MutableMap::filter

Returns a MutableMap containing the values of the current MutableMap that meet a supplied condition.

Description

public function filter(
  (function(Tv):bool) $fn,
): MutableMap<Tk,Tv>

Returns a MutableMap containing the values of the current MutableMap that meet a supplied condition.

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 MutableMap remain unchanged in the returned MutableMap.

Parameters

  • (function(Tv):bool) $fn - The callback containing the condition to apply to the current MutableMap values.

Return Values

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