How do you sort the output of Data::Dumper?

Set $Data::Dumper::Sortkeys = 1 to get Perl’s default sort order.
If you want to customize the order, set $Data::Dumper::Sortkeys to a reference to a subroutine that receives a reference to a hash as input, and outputs a reference to the list of the hash’s keys in the order you want them to appear.

# sort keys
$Data::Dumper::Sortkeys = 1;
print Dumper($obj);

# sort keys in reverse order - use either one
$Data::Dumper::Sortkeys = sub { [reverse sort keys %{$_[0]}] };
$Data::Dumper::Sortkeys = sub { [sort {$b cmp $a} keys %{$_[0]}] };
print Dumper($obj);