@abclist = qw(a b c d e);
@numlist = qw(1 3 5 7 9);
print sort {$a cmp $b} @abclist; // Default sort, prints 'a b c d e'
print sort {$b cmp $a} @abclist; // Prints 'e d c b a'
print sort {$b <=> $a} @numlist; // Prints '9 7 5 3 1'
print sort {$a == 7 ? -1 : ($b == 7 ? 1 : $a <=> $b)} @numlist;