#!/usr/bin/perl

use strict;
use warnings;

use Data::Dumper;

package Obj;

sub new {
    my ($class, @args) = @_;
    my $self = {};
    bless $self, $class;
    $self->init(@args);
    return $self;
}

sub init {
    my ($self, @args) = @_;
    %{$self} = (
        a => 10,
        @args,
    );

    return $self;
}

sub print_val_a {
   my $self = shift;
#   my $FHOUT = shift || "STDOUT";
#   print $FHOUT $self->{'a'} . "\n";
    print $self->{'a'} . "\n";

}

package main;

my $obj1 = Obj->new();
$obj1->print_val_a();

my $obj2 = Obj->new(a => 40);
$obj2->print_val_a();