You should really put the counter increment in the continue block, though, in case of next or redo. Compare:

my @arr = ('a'..'m');

my $i=0;
foreach (@arr) {
  # stuff goes here
  next if $i%4 == 0;
  print "$i: $_\n";
}
continue { ++$i }

$i = 0;
foreach (@arr) {
  # stuff goes here
  next if $i%4 == 0;
  print "$i: $_\n";
  ++$i;
}
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