Getting keys from a referenced hash

seaver has asked for the wisdom of the Perl Monks concerning the following question:

Dear all,

I have filled a PDB object with atoms:

$self->{'atoms'}{$number}=$atom;
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I want to access all the numbers like so:

my @numbers = keys %{$self->{'atoms'}};
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but in the line above, @numbers turns up empty...!?! I can reference any atom directly:

print $self->{'atoms'}{'2000'}."\n";
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But just cannot get a list of the numbers, Im sure ive misunderstood something about this, but i dont know what?

cheers
Sam

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Re: Getting keys from a referenced hash by rkg (Hermit) on Sep 23, 2003 at 19:13 UTC
just curious -- what is a PDB? rkg Updated -- protein data bank http://www.rcsb.org/pdb/ got it, sorry for the post	[reply]
Re: Getting keys from a referenced hash by seaver (Pilgrim) on Sep 23, 2003 at 17:20 UTC
forget it, I found a typo: `$self->{'$atoms'}{$number}=$atom;` [download] whoops, its working now. cheers Sam	[reply] [d/l]
Re: Re: Getting keys from a referenced hash by dragonchild (Archbishop) on Sep 23, 2003 at 17:31 UTC
That's one good reason to use the auto-quoting mechanism of {} as a hash de-referencer. :-) ------ We are the carpenters and bricklayers of the Information Age. The idea is a little like C++ templates, except not quite so brain-meltingly complicated. -- TheDamian, Exegesis 6 Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.	[reply]