Re^2: Exponential Function Programming

[Dominus]

sub my_factorial {
    ...
    if($n == 0) {
        $r=0;
    }
    return $r;
}

Your function says that 0 factorial is 0. But it's not; it's 1.

[blazar]

Perl 6 is very generous in this:

pugs> sub postfix:<!> (Int $n) { [*] 1..$n }
undef
pugs> say $_! for ^10
1
1
2
6
24
120
720
5040
40320
362880
undef

(I personally believe that I've posted this before here and in different media, but that's jut because it's quite about the only thing I can actually do in pugs ATM.)