use strict;
use Data::Dumper;

my @res = grep $_ split(",", "a,b,c,d,,f,,h");
print Dumper(\@res);

my @res2 = grep { $_ } split(",", "a,b,c,d,,f,,h");
print Dumper(\@res2);

##</code><code>##

$VAR1 = [
          'a',
          'c'
        ];
$VAR1 = [
          'a',
          'b',
          'c',
          'd',
          'f',
          'h'
        ];