$ perl -Mstrict -Mwarnings -e '
    my @array = "a" .. "z";
    my $n = 10;
    print $array[$_] for grep { ! (($_ + 1) % $n) } 0 .. $#array;
'
jt

##</code><code>##

$ perl -Mstrict -Mwarnings -e '
    my @array = "a" .. "z";
    my $n = 10;
    print map { $array[$_] . (($_ + 1) % $n ? "" : "\n") } 0 .. $#array;
'
abcdefghij
klmnopqrst
uvwxyz