use strict;
use warnings;
use Data::Dump::Streamer;

my @arr = ([11, 22, [[]]], [333, 444, []], [6666, 7777, []]);

push @{$arr[0][2][0]}, 3;
Dump \@arr;

@arr = ([11, 22], [333, 444], [6666, 7777]);

push @{$arr[0][2][0]}, 3;
Dump \@arr;

##</code><code>##

$ARRAY1 = [
            [
              11,
              22,
              [ [ 3 ] ]
            ],
            [
              333,
              444,
              []
            ],
            [
              6666,
              7777,
              []
            ]
          ];
$ARRAY1 = [
            [
              11,
              22,
              [ [ 3 ] ]
            ],
            [
              333,
              444
            ],
            [
              6666,
              7777
            ]
          ];