Another possibility, using defined or instead of disabling warnings.

use v5.16;
use warnings;

my @arr=qw/a b c d e/; 
my @bar = qw/12 34 56/; 
my $i = 0;

while ($i<($#arr+2)) { 
    say "\t \$i: $i"; 
    say "\t\t ", $arr[$i] // q{}, 
           ", ", $bar[$i] // q{};
    ++$i; 
}
[download]