fbrm@monastery:~$ perl -MData::Dumper -E '$Q=$A[4][6]; say Dumper \@A'
$VAR1 = [
          undef,
          undef,
          undef,
          undef,
          []
        ];

##</code><code>##

fbrm@monastery:~$ perl -MData::Dumper -E '$A[4]="hi"; say Dumper \@A'
$VAR1 = [
          undef,
          undef,
          undef,
          undef,
          'hi'
        ];