use warnings; use strict; my $value = "A\tB\tC\tD\tE\tF\t\t\t\t\t\t"; my @flds = split(/\t/, $value); $flds[16] = undef; $flds[8] = 0; print scalar @flds; __END__ Modification of a read-only value attempted at split.pl line 7.