use Data::Dumper;
@array = (1,2,3);
@brray = (4,5,6);

print Dumper [ \(@array,@brray) ];
print Dumper [ \((@array),@brray) ];

__END__
$VAR1 = [
          [
            1,
            2,
            3
          ],
          [
            4,
            5,
            6
          ]
        ];
$VAR1 = [
          \1,
          \2,
          \3,
          [
            4,
            5,
            6
          ]
        ];
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Update: oops, this should be a follow-up to BrowserUk's reply...