my $result = invert($string);
[download]

cLive ;-) - see above

Not quite. A list grep in a scalar context return the size of the list.

sub invert {
    #23456789012345678901234567890
    grep/[^\Q@_\E]/,map{chr}1..255
};

$inverted = invert( 'Just Another Perl Hacker!' );

print $inverted;
237
[download]

237 + 18 (unique characters in the string) = 255.

---

Examine what is said, not who speaks.

"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail

I actually already did toy with the idea of interpolating the output of grep into a string, but it turned out to fail to gain any ground; it works, but it's no shorter, plus to get identical output you would have to also set $" to '' (empty string), which takes additional keystrokes..

My 37 keystroke method:

sub invert {
    #234567890123456789012345678901234567
    join'',grep/[^\Q@_\E]/,map{chr}1..255
}
[download]

And now without join, but with double-quotish interpolation:

sub invert {
    #234567890123456789012345678901234567
    "@{[grep/[^\Q@_\E]/,map{chr}1..255]}"
}
[download]




Dave

Huh? grep() in scalar context returns a number, not a join()ed list of elements that passed through. And print() doesn't "force scalar context" -- in fact, it invokes list context, which is the only reason why print invert($string) works.
_____________________________________________________
Jeff[japhy]Pinyan: Perl, regex, and perl hacker, who'd like a job (NYC-area)
s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;