HoH Sorting by value

[Anonymous Monk]

I have a Hash of Hashes that I need to sort by a value. I have been checking out other posts, the perldocs, and trying different things but can't quite get it.

My data is as follows:
{ss_number}
 {employee_number}
  {years_employed}

I need to sort numerically according to the values in the years_employed.

[broquaint]

This should give you a sorted list of keys for your HoHoH

my @sorted = sort {
    $hash{$a}->{employee_number}->{years_employed}
    <=>
    $hash{$b}->{employee_number}->{years_employed}
} keys %hash;

HTH

_________
broquaint

[Anonymous Monk]

Is there any way to do this without creating a new array of the sorted values? I really do appreciate the help, but that wasn't what I was hoping for.

[Chmrr]

Hashes themselves cannot be sorted -- the closest one can get is to sort either the keys or the values of the hash, then iterate through them. See perldoc -q "sort a hash"

perl -pe '"I lo*`+$^X$\"$]!$/"=~m%(.*)%s;$_=$1;y^`+*^e v^#$&V"+@( NO CARRIER'

[rdfield]

Take broquaint's answer, remove the assignment, add a loop and a print. Job done.

Or do you just want the code:

my %hash;
while (<DATA>) {
   my @data = split;
   $hash{$data[0]}->{employee_number} = $data[1];
   $hash{$data[0]}->{years_employed} = $data[2];
}
foreach (sort {
              $hash{$a}->{years_employed}
              <=>
              $hash{$b}->{years_employed}
              } keys %hash) {
   print "$_ $hash{$_}->{employee_number} $hash{$_}->{years_employed}\
+n";
};

__DATA__
SS123 EMP123 3
SS234 EMP124 2
SS456 EMP125 1

prints

SS456 EMP125 1
SS234 EMP124 2
SS123 EMP123 3

rdfield

[Anonymous Monk]

Maybe I wasn't specific enough in my original question. Given the data above, I would like to print each ss_number, employee_number, & years_employed only sorted by years_employed. In other words, I would like this, only sorted:



foreach my $ss_number {keys %my_hash} {
  print "$my_hash{$ss_number}{$employee_number}\n";
}

[Thelonius]

Your data structure doesn't look right to me, unless you really want to have multiple employee_numbers per ss_number.

Probably you want a hash with ss_number as the key and the value as either an array ref or hash ref with all the values associated with that ss_number. E.g.

 $myhash{'555236801'} = [3035, 2];
or
 $myhash{'555236801'} = { empno => 3035, years => 2 };

Anyway, one easy way to get what you want is like this (at least on Unix (using the latter data structure:

  open SORTEDOUT, "|sort +2" or die "cannot open sort: $!\n";
  for (keys %myhash) {
    print SORTEDOUT $_, " ", $myhash{$_}{empno}, " ", $myhash{$_}{year
+s}, "\n";
  }
  close (SORTEDOUT) or die "Error on sort: $!\n";