use strict;
use warnings;

my @array = ( 1 .. 9 );
my @newArray =
   map {
           [
               exists $array[ 2 * $_ + 1 ]
               ? ( $array[ 2 * $_ ], $array[ 2 * $_ + 1 ] )
               : $array[ 2 * $_ ]
           ]
       }
   0 .. $#array / 2;

foreach my $raSubArray ( @newArray )
{
    local $" = q{, };
    print qq{[ @$raSubArray ]\n};
}

##</code><code>##

[ 1, 2 ]
[ 3, 4 ]
[ 5, 6 ]
[ 7, 8 ]
[ 9 ]