Returns a ConstMap after an operation has been applied to each value in the current ConstMap


public function map<Tu>(
  (function(Tv):Tu) $fn,
): ConstMap<Tk, Tu>;

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

The keys will remain unchanged from the current ConstMap to the returned ConstMap.


  • (function(Tv):Tu) $fn - The callback containing the operation to apply to the current ConstMap values.

Return Values