For loops in perl have two styles. The first is the c-style loop, the other is a map. One often uses the latter style a lot more often.
map { $_ + 1 } (@list); sub sum_of_squared_pairs {
reduce { $a + $b } map { $_ * $_ } grep { $_ % 2 == 0 } @_
}
sub schwartzian_transform {
map { $_->[0] }
sort { $a->[1] <=> $b->[1] } # use numeric comparison
map { [$_, length $_] } # calculate the length of the string
@_
}