Re^2: Hash value sorting

Awesome, sorted with one minor adjustment to your code; I had to dereference the conditions of the sort because it was sorting by the scalar reference address. I changed it to:

foreach my $key (
    sort {
        ${$self->{_counts}{$a}} <=> ${$self->{_counts}{$b}}
    } keys %{ $self->{_counts} }
[download]

Thanks so much for the help.

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Re^3: Hash value sorting by greengaroo (Hermit) on Aug 14, 2012 at 12:57 UTC
Try this: `foreach my $key ( sort { $self->{_counts}->{$a} <=> $self->{_counts}->{$b} } keys %{ $self->{_counts} }` [download] If you do $self->{_counts}{$b}, Perl thinks $self->{_counts} is a real Hash, not an HashRef. If you use the arrow to dereference, it is easier to read. Take my advice. I don't use it anyway. -- greengaroo	[reply] [d/l]
Re^4: Hash value sorting by daxim (Curate) on Aug 14, 2012 at 13:34 UTC
What you say is wrong. Quoting Arrow Rule in perlreftut: In between two subscripts, the arrow is optional.	[reply]
Re^3: Hash value sorting by daxim (Curate) on Aug 14, 2012 at 13:44 UTC
That code collides with your explanation of the data structure in 987336. Only one can be correct. In the constructor I see you initialise the field _counts with a hash reference. Where do you now get a scalar reference from? It would help if you dump $self before sorting, so we can see what the data structure really looks like. `use Data::Dumper; print Dumper $self;` [download]	[reply] [d/l]
Re^4: Hash value sorting by iHutch105 (Initiate) on Aug 14, 2012 at 15:41 UTC
You're absolutely right and I've found the problem. I made a mistake whenever I was creating/adding to values in the hash. I had this line: `${$self->{_counts}{$key}} += $value;` [download] This was where the scalar ref was coming from. I should note, key and value are parameter passed in, representing the obvious. This line explains why I had to do some extra, dodgy dereferencing later on and, of course, should have read: `$self->{_counts}{$key} += $value;` [download] All seems to be sorted now. Code looks a lot tidier too. First time I've really used references much but it's been a good learning experience. Thanks to all for the help and suggestions.	[reply] [d/l] [select]