foreach (0..$#{$object_ref->{array_ref}}) {
   printf("%d %s\n", $_, $object_ref->{array_ref}[$_]);
}

##</code><code>##

my $array = $object_ref->{array_ref};
foreach (0..$#$array) {
   printf("%d %s\n", $_, $array->[$_]);
}

##</code><code>##

my $array = $object_ref->{array_ref};
foreach my $idx (0..$#$array) {
   foreach my $ele ($array->[$idx]) {
      printf("%d %s\n", $idx, $ele);
   }
}