robertw has asked for the wisdom of the Perl Monks concerning the following question:

Dear Perlmonks, I have this huge hash that contains many five character keys, I want to make a subroutine that: if i give it for example two characters will foreach hash key calculate how many percent matches: if 1 character is in the hash key it is 1/5, with two it is 2/5 and multiply that number with the number associated with the hash key it has that many percent match with. Does anybody know how I could build such a thing or give helpful advice:)? Thank you so much in advance.

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Re: Perl hash comparison
by Kenosis (Priest) on Aug 17, 2012 at 00:25 UTC

    Perhaps I'm misunderstanding your issue's description, but it sounds like the following: given a set of characters and a hash key, return (chars in key / 5) * $hash{key}. If this is the case, perhaps the following will work for you:

    use Modern::Perl;

my %hash = (
    ABCDE => 12,
    FGHIJ => 7,
    KLMNO => 2
);

say getMatchResult( 'AC', 'ABCDE' );

sub getMatchResult {
    my ( $find, $key ) = @_;
    my $matches = () = $key =~ /[$find]/ig;

    ( $matches / 5 ) * $hash{$key};
}

    [download]

    Output:

    4.8

    [download]

    Hope this helps!

    Update: Thanks to hmb for suggesting the goatse operator (and character class). It timed faster than my iterative solution w/regex.

[reply]
[d/l]
[select]
      #my $matches;
#$matches += $key =~ /$1/i while $find =~ /(.)/g;

# or the "rolex" operator!
my $match =()= $key=~/[$find]/ig;

      [download]
[reply]
[d/l]

        This is a good suggestion; I'll make the change in the script.

[reply]
Re: Perl hash comparison
by Anonymous Monk on Aug 16, 2012 at 20:14 UTC
    Have you heard of keys? Any more questions?
[reply]

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