Re: iterate through a hash with two keys

[LanX]

Not sure what you want ...

... if $label should be variable, try

 print $hash{$_}{$label} for keys %hash

Update:

or shorter

 print $_->{$label} for values %hash

errata

s/values/keys/ in first expression

[fionbarr]

I didn't ask the question properly. I want to print all the labels and values for each of 'a' .. 'h' the label is a variable. I am filling this hash like: $hash{a}{$label} = $value; where $label is a text string.

[BillKSmith]

This may be what you want.

use strict;
use warnings;
my $label1 = 'L1';
my $label2 = 'L2';
my %hash;
@hash{'a' .. 'h'} = (
    {$label1 => 1 },
    {$label1 => 2 },
    {$label2 => 3 },
    {$label1 => 4 },
    {$label2 => 5 },
    {$label1 => 6 },
    {$label2 => 7 },
    {$label1 => 8 },
);
while ( my( $key,$subhash ) = each %hash) {
    print "$key: $subhash->{$label1}\n" if exists $subhash->{$label1};
}

OUTPUT:

a: 1
d: 4
h: 8
b: 2
f: 6

[LanX]

> I didn't ask the question properly.

indeed!

> I want to print all the labels and values for each of a .. h

  DB<103> @hash{$_} = {x=>$x++,y=>$x++} for a..h
 => ""

  DB<112> while ( my ($k1,$v1) = each %hash ) {
            while ( my ($k2,$v2) = each %$v1 ) {
              print "$k1 - $k2 -$v2\n"
            }
          }
e - y -25
e - x -24
a - y -17
a - x -16
d - y -23
d - x -22
... # and so on

But are you looking for Data::Dumper ?

UPDATE

  DB<106> print Dumper \%hash
$VAR1 = {
          'e' => {
                   'y' => 9,
                   'x' => 8
                 },
          'a' => {
                   'y' => 1,
                   'x' => 0
                 },
          'd' => {
                   'y' => 7,
                   'x' => 6
                 },
          'c' => {
                   'y' => 5,
                   'x' => 4
                 },
...

FWIW I prefer Data::Dump or YAML¹, but Data::Dumper is core.

¹) interesting Module::Build::YAML was first released with perl 5.009004

UPDATE YAML

  DB<106> use YAML::Tiny
 => 0

  DB<107> Dump(\%hash) 
---
a:
  x: 16
  y: 17
b:
  x: 18
  y: 19
c:
  x: 20
  y: 21
d:
  x: 22
  y: 23
...

[fionbarr]

doing it like this:

my @array = qw( FirstName     LastName     MiddleName     LegalInd 
            DateOfBirth     Sex         Race         Ethnicity
             Height         Weight         Build         Eyes 
            Hair         SocSecNo     MaritalStatus    PlaceOfBirthCit
+y
            PlaceOfBirthState         AddressType    DfAdate
            StreetNumber     StreetName     StreetType    City 
            State         Zip );

    for (@array) {    
        $xml_writer->dataElement("$_"     => $t{A}{$_});    
    }