$ perl -MData::Dumper -wE'@a=qw(1 2 3); @b=qw(4 5 6);add1(@a, @b);say Dumper \@a, \@b;sub add1{++$_ for @_}'
$VAR1 = [
          '2',
          '3',
          '4'
        ];
$VAR2 = [
          '5',
          '6',
          '7'
        ];