HH\KeyedIterable::mapWithKey

Returns a KeyedIterable containing the values after an operation has been applied to each key and value in the current KeyedIterable

public function mapWithKey<Tu>(
  (function(Tk,Tv):Tu) $callback,
):     KeyedIterable<Tk, Tu>;

Every key and value in the current KeyedIterable is affected by a call to mapWithKey(), unlike filterWithKey() where only values that meet a certain criteria are affected.

Parameters

  • (function(Tk,Tv):Tu) $callback

Return Values