http://www.perlmonks.org?node_id=1037856


in reply to Re: Hash dereferencing in a loop
in thread Hash dereferencing in a loop

Also, you may encounter “double-$” syntax:   $$hashref{$key}.

The two are equivalent, and notice in this case that the -> symbol does not appear.   Recommend that you consistently use one or the other (your choice) in your programs.   (Double-$ is less common.)

Also note that, in cases where a sequence of -> symbols would technically be required, to reference elements of a hashref that contains hashrefs, Perl allows the additional ones to be omitted.