3/18    In Perl, I'm using a hash of a hash like the following:
        my $w=$CATEGORY{$c};
        my %w=%$w;
        But after turning on strict, it no longer works and reports
Can't use an undefined value as a HASH reference at bin/categorize.pl line 72.
        What am I doing wrong? Thanks.
        \_ What does $CATEGORY{$c} return? A hash?  you probably want a
           reference to it, not a copy.  And that would help you sort out
           the access on the next line.
        \_ You probably mean "%w = %{$w}", but why not just use the pointer?
           -scotsman
                \_ I'd like to use %w like $w{$key}=$val. So can I actually
                   reference/deference in Perl? Problem with Perl is I don't
                   know when I'm copying by value or copying by reference...
                   \_ Well, the first line there is copying by reference.  My
                      correction of the second line copies by value.  The %{}
                      is a dereference as well as a "cast". -scotsman
                        \_ same problem even with cast, whats wrong?
                        \_ ok I just found out that when I set to use strict,
                           %CATEGORY becomes empty even though I made it
                           public by "use vars qw (%CATEGORY)". So now
                           I'm just scratching my head...
                NEVERMIND I found it's a logic problem and _/
                has NOTHING to do with use strict. I really
                like "use strict"! I've caught a lot of bugs
                with it.