use strict;

my (@array,$array);
my $foo = foo->new();

# won't change
@array = $foo->get_array;
@array = ('a'..'f');
print join(',',$foo->get_array),"\n";

# won't change
$array = $foo->get_array_ref;
$array = [('a'..'f')];
print join(',',$foo->get_array),"\n";

# won't change
$array = $foo->{_array};
$array = [('a'..'f')];
print join(',',$foo->get_array),"\n";

# will change
$foo->{_array} = [('a'..'f')];
print join(',',$foo->get_array),"\n";


package foo;
use strict;

sub new { bless { _array => [(0..9)] }, shift }

sub get_array     { @{shift->{_array}} }
sub get_array_ref { shift->{_array}    }