use strict;
use warnings;

# usually this is defined inside a perl module
# at ./Whatever/Package.pm
package Whatever::Package;

# this is the constructor. generally called new but is not a rule 
sub new{
	# we will receive the class name as first argument
	my $class = shift;
	# and just need to return a reference (an anonymous hash {} in this case) blessed into $class
	return bless {}, $class;
}

sub first {
	my $self = shift;
	print "We are inside package ",__PACKAGE__,
			" we received \$self because it is blessed into ",ref $self,"\n";
}

# usually this is defined inside a perl module
# at ./Another/Example/Package.pm
package Another::Example::Package;

# note the same NAME for the sub
sub first {
	my $self = shift;
	print "This method will no be called unless the object is blessed into Another::Example::Package";
}

# usually the script will use Whatever::Package (defined inside a perl module ./Whatever/Package.pm)
# but we can merely switch back to the default package 'main'
package main;

# again a sub with the same name
sub first{ 
	print "We are inside package ",__PACKAGE__," I'm not a method but a bare lone sub\n";
}

# test the local sub
first();

# let 'instanciate' an object of the Whatever::Package class
my $obj = Whatever::Package->new();

print "\$obj is now a blessed reference. It is blessed into ",ref $obj,"\n";

# above we have 3 subs named first. Which one will be called?
$obj->first();