Hash in Array

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

#!/usr/bin/perl -W
use Data::Dumper;

my %customer_type;
#my @exist_customer_id;
my @customer_id = ('E1', 'E2');
my @customer_count = ('1', '2');
foreach (@customer_count){                        
    foreach(@customer_id){                            
        #push(@exist_customer_id, $_);
        $customer_type{$_} =  "valid";
    }
    push(@customer_type, \%customer_type);
}    



print STDOUT " VALUE   " . Dumper(@customer_type);
[download]

When i run this code it gives the following output..

 VALUE   $VAR1 = {
          'E2' => 'valid',
          'E1' => 'valid'
        };
$VAR2 = $VAR1;
[download]

Why it showing $var2 = $var1 ? While i expected this

$VAR2 = {
          'E2' => 'valid',
          'E1' => 'valid'
        };
[download]

Can you guide how to get above output..

Comment on Hash in Array Select or Download Code

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Re: Hash in Array by kennethk (Abbot) on Jan 05, 2010 at 15:42 UTC
If I understand your intent, you are having scoping problems. As I understand it, on each iteration of your `@customer_count` loop, you want to build a new hash. That means you are having a scoping issue. Rather than scoping the `%customer_type` hash at the script level, you want to declare the new object at the level where you want an empty, new version to appear. If that is unclear, you may garner insight from Private Variables via my(). In any case, one fix would be: `#!/usr/bin/perl use strict; use warnings; use Data::Dumper; #my %customer_type; #my @exist_customer_id; my @customer_id = ('E1', 'E2'); my @customer_count = ('1', '2'); my @customer_type; foreach (@customer_count){ my %customer_type; foreach(@customer_id){ #push(@exist_customer_id, $_); $customer_type{$_} = "valid"; } push(@customer_type, \%customer_type); } print STDOUT " VALUE " . Dumper(@customer_type);` [download] Note as well my use of `use strict;`, which is generally considered to be a Good Thing(TM).	[reply] [d/l] [select]
Re: Hash in Array by JavaFan (Canon) on Jan 05, 2010 at 13:20 UTC
You are pushing a reference to the same hash twice on the array. So why shouldn't it tell you that? If you want different hashes, put the `my %customer_type;` inside the loop.	[reply] [d/l]