my @arr = qw/ foo foozle bar bar2 foo bar foo /;

  for (my $i=0; $i<@arr; $i++) {
    splice(@arr, $i, 1) if ($arr[$i] =~ /bar/);
  }
  print "$_\n" for (@arr);

  ## output: bar2 is NOT removed

##</code><code>##

  @chroms = grep { ! /[pqxy]/i } @chroms;

##</code><code>##

  for (my $i=0; $i<@chroms; $i++) {
    splice(@chroms, $i--, 1) if not $chroms[$i] =~ /[pqxy]/i;
  }                 ####