Re: Dereferencing a Hash of Arrays

You have two problems:

my %alphabet = \( 'a' => @atags, 'b' => @btags, );
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You are using a list reference which produces a list of references, so your hash is the same as:

my %alphabet = (
     \'a' => \@atags,
     \'b' => \@btags,
             );
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say for @{values %alphabet};
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The construct @{} dereferences an array reference but values %alphabet does not return an array reference, it returns a list.

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Re^2: Dereferencing a Hash of Arrays by toro (Beadle) on Jun 14, 2011 at 07:33 UTC
input: `my @atags = qw( 1 2 3 4 ); my @btags = qw( 9 8 7 6 ); my %alphabet = ( 'a' => \@atags, 'b' => \@btags, ); say for values %alphabet;` [download] output: `ARRAY(0x8376dd8) ARRAY(0x837f298)` [download] UPDATE: I did `say for values %alphabet` in response to an earlier version of Re^1 without the `@{...}`. My original code was `my %alphabet = ('a', \@atags, 'b', \@btags); say for @{values %alphabet};` which prints an error similar to the OP.	[reply] [d/l] [select]
Re^3: Dereferencing a Hash of Arrays by johngg (Canon) on Jun 14, 2011 at 10:40 UTC
The "values" are array references so you have to dereference them using `@{ ... }` to get the array elements. You can also get there using keys and dereferencing the looked up value in the hash. knoppix@Microknoppix:~$ perl -MData::Dumper -Mstrict -wE ' > my @aTags = ( 1 .. 4 ); > my @bTags = reverse 6 .. 9; > my %alpha = ( a => \ @aTags, b => \ @bTags ); > print Data::Dumper->Dumpxs( [ \ %alpha ], [ qw{ alpha } ] ); > say q{-} x 20; > say qq{@{ $_ }} for values %alpha; > say q{-} x 20; > say qq{@{ $alpha{ $_ } }} for keys %alpha; > say q{-} x 20; > foreach my $arrayRef ( values %alpha ) > { > say for @{ $arrayRef }; > say q{-} x 20; > } > foreach my $key ( keys %alpha ) > { > say for @{ $alpha{ $key } }; > say q{-} x 20; > }' %alpha = ( 'a' => [ 1, 2, 3, 4 ], 'b' => [ 9, 8, 7, 6 ] ); -------------------- 1 2 3 4 9 8 7 6 -------------------- 1 2 3 4 9 8 7 6 -------------------- 1 2 3 4 -------------------- 9 8 7 6 -------------------- 1 2 3 4 -------------------- 9 8 7 6 -------------------- knoppix@Microknoppix:~$ [download] I hope this is helpful. Update:* Expanded the example code to show how to print one element per line as the OP's code seemed to want. Cheers, JohnGG	[reply] [d/l] [select]