dereference an array

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

Hi, I'm creating a links page with the links sorted into categories. I think the best way of handling the information is as follows:

while (<FH>) {
  my ($webaddress, $sitename, $sitedesc, $category) = split "\t";
  my @cc = ($webaddress, $sitename, $sitedesc);
  push @{ $sortmenu{$category} }, [$webaddress, $sitename, $sitedesc];
}
close FH;
[download]

however I'm not clear on how to dereference the array. I wonder if someone could please explain what I need to do

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Re: dereference an array by Corion (Patriarch) on Oct 22, 2007 at 14:32 UTC
See tye's References Quick Reference. Basically, if `$arr` is an array reference, `@$arr` gives you the referenced array and `$arr->[42]` gives you an element of it.	[reply] [d/l] [select]
Re: dereference an array by ikegami (Patriarch) on Oct 22, 2007 at 14:41 UTC
You have a hash of references to arrays keyed by category. Each array is a list of records. Each record is a reference to an array with three elements (web address, site name and site desc). `foreach my $category (sort keys %sortmenu) { foreach my $record (@{ $sortmenu{$category} }) { print "web address: $record->[0]\n"; print "site name: $record->[1]\n"; print "site desc: $record->[2]\n"; print "\n"; } }` [download] Data::Dumper may aid you in visualizing your data structure. `use Data::Dumper; print(Dumper(\%sortmenu));` [download]	[reply] [d/l] [select]
Re^2: dereference an array by Anonymous Monk on Oct 22, 2007 at 14:45 UTC
That's a very nice explanation, thanks very much for your time - this is nearly on the verge of blowing a cerebral gasket!! :)	[reply]
Re: dereference an array by gamache (Friar) on Oct 22, 2007 at 15:07 UTC
Reference an array (or anything else) by putting a backslash in front of it: `push @{ $sortmenu{$category} }, \@cc;` [download] and dereference an arrayref by wrapping the it in @{}: `my @a = @{$arrayref};` [download]	[reply] [d/l] [select]