Undefined Array Reference

[Anonymous Monk]

Monks, hi there!

I followed a node here while ago and one part of the code got me going, I wish someone could show me a better way to accomplish this issue, I can't figure it out. Is got to be a better and simpler way to do this.
It needs to place a space in the $ref_b to make sure consistency when generating a report out of this and avoid errors.

use strict;
use warnings;
use Data::Dumper;

my $ref_a = [
             [ qw/a b c/ ],
             [ qw/d e f/ ],
             [ qw/g h i/ ],
             [ qw/x y z/ ],
             [ qw/3 4 5/ ],
             [ qw/6 7 9/ ],
            ];

my $ref_b = [
             [ qw/j k l/ ],
             [ qw/m n o/ ],
             [ qw/p q r/ ],
            ];

for my $i (0..$#$ref_a) {
    push @{$ref_a->[$i]}, @{$ref_b->[$i]};
}
print Dumper($ref_a);