http://qs1969.pair.com?node_id=191727

gnu@perl has asked for the wisdom of the Perl Monks concerning the following question:

I have the following hash of hashes:
my %switch_hash = ( chrdex => { DEX => { '01-AUG-02' => 1, '03-AUG-02' => 3, } }, uslcgb5e2sm =>{ Greensboro => { '4-AUG-02' => 1, '6-AUG-02' => 2, } }, uslecat25e1 => { 'Atlanta II' => { '1-AUG-02' => 1, '2-AUG-02' => 3, '3-AUG-02' => 1, '4-AUG-02' => .25, } }, ); $rhent = \%switch_hash;
I want to do this:
my @dates = ( keys %{(keys %{(keys %$rhent)})} );
and I get this error:
Can't use string ("3") as a HASH ref while "strict refs" in use at ./x +cl3.pl line 301
Can something like this be done to get the key containing the date from the final hash? NOTE: There is a reason for using a reference, but that is beyond the scope of this question.