Problem iterating AoH

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi,
I am parsing a XML file using XML::Simple. It return a structure $configitem->{'config'}. It looks like this

$VAR1 = \[
            {
              'content' => 'Blocking',
              'type' => 'Blocking'
            },
            {
              'content' => 'P01',
              'type' => 'Priority'
            }
          ];
[download]

i am processing this structure to build HoA (%qryhash). I have listed the code below. in the foreach loop is executed only once. I need the following

print Dumper(\%qryhash);

$VAR1 = {
          'Blocking' => [
                          'Blocking'
                        ],
          'Priority' => [
                          'P01'
                        ]
        };
[download]

But i am getting only

print Dumper(\%qryhash);

$VAR1 = {
          'Blocking' => [
                          'Blocking'
                        ]
        };
[download]

Here is the code snippet.

sub extract_table_queries{
    my $configitem = $_[0];
    my @assigneearray = ();
       my %qryhash;
        print ref $configitem->{'config'};
    if (ref $configitem->{'config'} eq 'ARRAY'){
        @queries = @{$configitem->{'config'}};
        $i = 0;
        $count = @queries;
        foreach $q (@{$configitem->{'config'}}){
            my $value = $q->{'content'};
            my $param = $q->{'type'};
            
            #$value =~ s/^\s+|\s*$//g;
            $param = &return_param_name($param);

            push @{$qryhash{$param}}, $value;
        
            if (lc $param eq lc $configitem->{rollup}){
                push @rolluplist,$value;
            }
            
            my $tmp = sprintf("%-15s",$param); 
            print "------>$tmp: $value\n";

        }
    print Dumper(\%qryhash);
    print Dumper(\$configitem->{'config'});
exit;
        return(\%qryhash);
    }
}
[download]

Can anyone please find out the mistake in my code and help me out?

Comment on Problem iterating AoH Select or Download Code

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Re: Problem iterating AoH by bellaire (Hermit) on Nov 17, 2009 at 13:03 UTC
Your code works just fine for me, except that I had to define a return_param_name method to return its own first argument. Assuming that method doesn't do anything bizarre, your code should work as given. Here's my complete output: `ARRAY------>Blocking : Blocking ------>Priority : P01 $VAR1 = { 'Blocking' => [ 'Blocking' ], 'Priority' => [ 'P01' ] }; $VAR1 = \[ { 'content' => 'Blocking', 'type' => 'Blocking' }, { 'content' => 'P01', 'type' => 'Priority' } ];` [download]	[reply] [d/l]
Re: Problem iterating AoH by biohisham (Priest) on Nov 17, 2009 at 15:20 UTC
What is the $param returned for each 'type' key after the subroutine `&return_param_name`? I'd suggest you sprinkle some print statements around as follows and show what `&return_param_name` looks like, `my $value = $q->{'content'}; my $param = $q->{'type'}; print $param,"$/"; #<------------------Here #$value =~ s/^\s+\|\s$//g; $param = &return_param_name($param); print $param,"$/"; #<--------------------Here push @{$qryhash{$param}}, $value;` [download] Since your problem lays in converting an AoH to a HoA by iterating over the AoH, using the Dumped output you provided it is possible to iterate as follows: `#!/usr/local/bin/perl #title "Problem iterating AoH" use strict; use warnings; my @queries = ( { 'content'=>'Blocking', 'type' => 'blocking' }, { 'content'=>'p01', 'type'=>'Priority' } ); my %hash; for my $reference (@queries){ push @{$hash{$reference->{'type'}}},$reference->{'content'}; } use Data::Dumper; print Dumper(\@queries),"\n"; print Dumper(\%hash);` [download] OUTPUT:* `$VAR1 = [ { 'content' => 'Blocking', 'type' => 'blocking' }, { 'content' => 'p01', 'type' => 'Priority' } ]; $VAR1 = { 'blocking' => [ 'Blocking' ], 'Priority' => [ 'p01' ] };` [download] Excellence is an Endeavor of Persistence. Chance Favors a Prepared Mind.	[reply] [d/l] [select]