Re: Count values in a hash

You need to dereference the array.

use warnings;
use strict;

my %hash = (
          'A2M' => [
                     'C972Y',
                     'A423W'
                   ],
          'A4GALT' => [
                        'W261X',
                        'P251L',
                        'P251S',
                        'A219V'
                      ]
);

for my $k (sort keys %hash) {
    print "Current key is\t" . $k . "\n";
    my $totalcount = @{ $hash{$k} };
    my $xcount = grep { /X/ } @{ $hash{$k} };
    print $k . "\t" . $totalcount . "\t" . $xcount . "\n";
}

__END__

Current key is  A2M
A2M     2       0
Current key is  A4GALT
A4GALT  4       1
[download]

See also: grep and perldsc

Comment on Re: Count values in a hash Download Code

Replies are listed 'Best First'.
Re^2: Count values in a hash by sophix (Sexton) on Jan 11, 2011 at 18:01 UTC
Thank you very much, toolic. Does `@{ $hash{$k} }` work as a reference? What does `@{}` do?	[reply] [d/l] [select]
Re^3: Count values in a hash by toolic (Bishop) on Jan 11, 2011 at 18:05 UTC
What does @{} do? It dereferences the array. See also: perlref perlreftut References quick reference	[reply]
Re^4: Count values in a hash by sophix (Sexton) on Jan 11, 2011 at 18:11 UTC
Ah, okay. Then this explains why the array did not work in my case. I need to dereference it as to work on it. Thanks for the links, I'll check them out now. I guess a good knowledge of using references in Perl would help me solve many of my problems.	[reply]