Map containing the values of the current
Map that meet
a supplied condition applied to its keys and values
public function filterWithKey(
): Map<Tk, Tv>;
Only keys and values that meet a certain criteria are affected by a call to
filterWithKey(), while all values are affected by a call to
The keys associated with the current
Map remain unchanged in the
Map; the keys will be used in the filtering process only.
(function(Tk,Tv):bool) $callback - The callback containing the condition to apply to the
Map keys and values.
Map<Tk, Tv> - a
Map containing the values after a user-specified condition
is applied to the keys and values of the current