Hrmm... I might be really off here but wouldn't this construct be simpler? (pretty new to perl as well and not fully conversant with the intricacies of hashes)

#!/usr/bin/perl -w
use strict;

my %data;

open DB, "db.txt";

while (<DB>) {
    @_ = split/[\t,|\n]/;
    $data{ $_[0] } = { @_[1..$#_] };
}

close DB;

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I tried shift @_ then just @_ in the right side of the equation and learned again that it's evaluated all as one not left to right ;). Anyways, this way you get a data structure something like this:

# pseudo representation
615 = (
      MNH  => 36.00
      USED => 12.00
      PB   => 50.00
      )

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Some examples on how to access it.

keys %data            # 614, 615, 616
$data{615}            # an anon hashref
$data{615}{USED}      # 12.00
keys %{ $data{615} }  # MNH, USED, PB

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Printing out the structure (I've never used DATA::Dumper might it apply here?):

for my $key (keys %data) {
    print "\n$key";
    my $h_ref = $data{$key};
    printf "\t%s\t%6.2f\n", $_, $h_ref->{$_} for keys %$h_ref;
}

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tilly suggested the $h_ref for speed (less hash lookups per inner loop iteration), I'm declaring inside because I'm lazy and don't want to undef it after.

It's output:

614     MNH      16.00
        USED     32.00
        PB       50.00

615     MNH      36.00
        USED     12.00
        PB       50.00

616     MNH      96.00
        USED      2.00
        PB       10.00

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I didn't do any of the null checks, but that's pretty trivial to add. The \n in the split handles getting rid of the newline.. chomp may be better, I'm not sure.

Update

Just for fun I one lined the db to hash (not exactly efficient):

$data{ (split/\t/)[0] } = { (split/[\t,|\n]/)[1..6] } while <DB>;

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Update 2

Oops, fixed up what Hofmator suggested... I swear I knew that about char classes I just didn't know split well enough and it sort of evolved that way as I worked through ;). Thanks.

In reply to Re: Stuck while learning about the hash by Arguile
in thread Stuck while learning about the hash by Stamp_Guy

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