my ($largest, $smallest) = (-9e9,9e9);                          #   initialize to the wrong extremes
    ...
        for my $v (@array) {                                    #   [anonymous monk]'s [id://1203660]: single pass through loop, without sorting; more efficient than brostad's single sort
            $largest = $v   if $v > $largest;
            $smallest = $v  if $v < $smallest;
        }