Assuming you dont have undefined values or references as the values of @arr you can do this: 

use Data::Dumper;
%fruits=();
@arr = ([1,1],[1,2],[3,5],[6,7]);
for (@arr)
{
    my ($k,$v)=@$_;
    if (ref $fruits{$k}) {
        push @{$fruits{$k}},$v;
    } else{
        $v=[$fruits{$k},$v] if (defined $fruits{$k});
        $fruits{$k}=$v;
    }
}

print Dumper(\%fruits);
__END__
$VAR1 = {
          '6' => 7,
          '1' => [
                   1,
                   2
                 ],
          '3' => 5
        };

[download]

Which is IMO a pattern perl programmers should be familiar with as it comes up fairly often. When only a few values will be lists the overhead of forcing each one to be an array can be unacceptable, but a hybrid works reasonably well. Imo generating stringified lists is not too desirable, but thats just me being a generalist, I suspect it could be a reasonable approach for some problems.

---
demerphq

In reply to Re: How to store this value in Hash ? by demerphq
in thread How to store this value in Hash ? by gube

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