It's possible, but it's not doing what you think it is (as use warnings will show you).

$ perl -Mwarnings -e '%h = { foo => [ 1 .. 3] }'
Reference found where even-sized list expected at -e line 1.
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You have the wrong kind of brackets. You want:

my %hash = (
              key1 => [a1_ref,a1_ref],
              key2 => [a3_ref,a4_ref]
           );
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Having created your data structure, Data::Dumper will be invaluable for exploring it and perldsc is full of information about how to get values out of it.

Do you think of something like this?

my %hash = (
    key1 => [\@a1_ref, \@a2_ref],
    key2 => [\@a3_ref, \@a4_ref],
);
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If you want to use the a2_ref for instanze, $hash{key1}->[1] could be what you want.

Edit: As an example:

#!/usr/bin/perl
use strict;
use warnings;

my @array1 = ( 1 .. 6 );
my @array2 = ( 7 .. 9 );
my @array3 = ( 'aa' .. 'af' );
my @array4 = ( 'b0' .. 'b9' );

my %hash = (
    key1 => [\@array1, \@array2],
    key2 => [\@array3, \@array4],
);

print "hoffentlich eine acht: ", $hash{key1}->[1]->[1], "\n";
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It prints "hoffentlich eine acht: 8".

I am trying to do somthing like this <code> open my $fh, '<', $filename or die "$filename: $!\n"; while (<$fh>) { chomp; ($key, $value) = split /\|/, $_; push @{$hash_merge{$key}},$value; print "key for $key merge values $hash_merge{$key}->[0]1 \n"; #file looks like

sorry some typo mistake I am trying to do somthing like this

 open my $fh, '<', $filename or die "$filename: $!\n"; while (<$fh>) {
+ chomp; ($key, $value) = split /\|/, $_; push @{$hash_merge{$key}},$v
+alue; print "key for $key merge values $hash_merge{$key}->[0]1 \n";

 #file looks like 

9344220001|sei10720013,21/07/2009-00-00-00,23/07/2009-12-34-44
9344220001|sei10720014,23/07/2009-20-00-23
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