use Data::Dumper;
use strict;
use warnings;
$|++;
printf "D::D version %s\n",Data::Dumper->VERSION;
for my $sk (0,1) {
    print "\$Data::Dumper::Sortkeys=$sk\n";
    $Data::Dumper::Sortkeys=$sk;
    for my $up (1,0) {
        print "\$Data::Dumper::Useperl=$up\n";
        $Data::Dumper::Useperl=$up;
        my %rev;
        my %name;

        print "Dumper:\n",Dumper(\%rev,\%name),"\n";
    }
}
print "Done\n";
__END__
D::D version 2.121
$Data::Dumper::Sortkeys=0
$Data::Dumper::Useperl=1
Dumper:
$VAR1 = {};
$VAR2 = {};

$Data::Dumper::Useperl=0
Dumper:
$VAR1 = {};
$VAR2 = {};

$Data::Dumper::Sortkeys=1
$Data::Dumper::Useperl=1
Dumper:
$VAR1 = {};
$VAR2 = {};

$Data::Dumper::Useperl=0
Use of uninitialized value in print at c:\temp\test_dd.pl line 15.
Dumper:
$VAR2 = {};
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