HH\Iterable::map
Returns an Iterable containing the values after an operation has been
applied to each value in the current Iterable
public function map<Tu>(
(function(Tv): Tu) $fn,
): Iterable<Tu>;
Every value in the current Iterable is affected by a call to map(),
unlike filter() where only values that meet a certain criteria are
affected.
Guide
Parameters
(function(Tv): Tu) $fn- The callback containing the operation to apply to theIterablevalues.
Returns
Iterable<Tu>- anIterablecontaining the values after a user-specified operation is applied.