my @strings = qw(
    aaaaa
    eeeee
    iiiii
    abcde
    aeiou
    bdfhj
);

my %regexes = (
    alternation => qr/a|A|e|E|i|I|o|O|u|U/,
    class       => qr/[AaEeIiOoUu]/
);

foreach my $string (@strings)
{
    print "$string:\n";
    while (my ($k, $r) = each %regexes)
    {
        print "\t$k - " . ($string =~ /$r/ ? 'YES' : 'NO') . $/;
    }
}
---------------
aaaaa:
        alternation - YES
        class - YES
eeeee:
        alternation - YES
        class - YES
iiiii:
        alternation - YES
        class - YES
abcde:
        alternation - YES
        class - YES
aeiou:
        alternation - YES
        class - YES
bdfhj:
        alternation - NO
        class - NO
[download]

Please give me a counter-case. As far as I can tell, the two regexes are identical, save that the alternation one is slower.

The OP was looking for strings that contain all of the vowels. Your code doesn't do that.

duff

In my defense, neither did the code I was referring to.

That is an interesting question - is there a way to have a regex take a character class and determine if the string contains all the characters in the class?

------
We are the carpenters and bricklayers of the Information Age.

Then there are Damian modules.... *sigh* ... that's not about being less-lazy -- that's about being on some really good drugs -- you know, there is no spoon. - flyingmoose