while (<DATA>){
    chomp;
    ($itemone) = split/,/; #split at comma
    $seen{$itemone}++;
}

foreach my $element (sort { $a <=> $b} keys %seen){
    print "$element\n";
}
exit;

__DATA__
1,ABC,X,1.203000e+02
1,ABC,Y,7.830000e+00
2,DEF,X,1.212400e+02
2,DEF,Y,8.810000e+00
3,GHI,X,1.180700e+02
3,GHI,Y,8.550000e+00
5,JKL,X,1.193500e+02
5,JKL,Y,7.270000e+00

[download]
you forgot to look at the keys for the seen hash, also look how I used $_ those chomp lines etc were real ugly.

-Waswas

In reply to Re: Sorting a hash. What am I doing wrong? by waswas-fng
in thread Sorting a hash. What am I doing wrong? by mndoci

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