Hi all,

I have a problem with OO Perl (I don't have too much experience). My problem with a simple example (pretty closed to mine).

My object has two attributes: one is a ref. to
an anonymous array and one to anonymous hash. The second one is initialized from the first one. From the main program, I create 2 objects giving an array ref. The problem is when I create the second object I am also overwriting the hash from the first one How can I avoid this? What did I misunderstand from object creation?

Thanks!

The class

package dogandcat;

use warnings;
use strict;
use Carp;

# Class data and methods
{

    # A list of all attributes with default values
    my %_attributes = (
        _data       => [],      # anonymous array
        _hash      => {},       # anonymous Hash
    );

    # Return list of all attributes
    sub _all_attributes {
        keys %_attributes;
    }

    # Return the default value
    sub _attribute_default {
        my ( $self, $attribute ) = @_;
        $_attributes{$attribute};
    }

    # Check if a given argument exists
    sub _arg_exist {
        my ( $self, %arg ) = @_;
        foreach my $arg ( keys %arg ) {
            unless ( grep /$arg/, keys %_attributes ) {
                croak("ERROR::: '$arg' is not a valid argument");
            }
        }
    }

}

# Constructor
sub new {
    my ( $class, %arg ) = @_;
    my $self = bless {}, $class;

    $self->_arg_exist(%arg);    # Check if all given args are ok

    # Set the attributes for the provided arguments
    foreach my $attribute ( $self->_all_attributes() ) {
        my ($argument) = ( $attribute =~ /^_(.*)/ );
        # Initilize to defaults
        $self->{$attribute} =
          $self->_attribute_default($attribute);    

        # Override defaults with arguments
        if ( exists $arg{$argument} ) {
            $self->{$attribute} = $arg{$argument};
        }
    }

 
     # Empty the hash loci
    %{$self->{_hash}} = ();
    
    # Getting the data from the array 
    # and storing the information in the hash
    $self->_get_hash ();   

    return $self;
}

# Accessors and Mutators

sub DESTROY {
    my ($self) = @_;
}

sub _get_hash {
    my ($self) = @_;
  
   foreach my $locus (@{$self->{_data}}) {
       my @elements = split (/:/, $locus);
       if ( $elements[0] ne '' or scalar @elements < 3 ) {
           ${$self->{_hash}}{ $elements[0] } = $elements[1];
       } else {
             croak ("ERROR");
       }
    }
  
}

1;
[download]

Main

Sorry for the bad practices

#!/usr/bin/perl

use strict;
use warnings;

use dogandcat;

my @cat = ("cat:a,b,c,d,e,f","cat2:g,h,i,j,k,l,m");
my @dog = ("dog1:1,2,3,4,5,6,7","dog2:21,22,23,24,25");

my $object1 = dogandcat->new (data =>\@cat);
print "this is cat data   \n", @{$object1->{_data}}, "\n";
print "this is cat keys   \n", keys %{$object1->{_hash}}, "\n";

my $object2 = dogandcat->new (data => \@dog);
print "this is dog data   \n", @{$object2->{_data}}, "\n";
print "this is dog keys   \n", keys %{$object2->{_hash}}, "\n";

print "\nbut....after creates the second object\n";

print "this is cat data   \n", @{$object1->{_data}}, "\n";
print "this should be cat keys   \n", keys %{$object1->{_hash}}, "\n";

print "this is dog data   \n", @{$object2->{_data}}, "\n";
print "this is dog keys   \n", keys %{$object2->{_hash}}, "\n";


exit;
[download]

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