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

I need to do a reg expression on a word to find out if it has letters: "a" "b" "c"

I think to get one letter I do this: 
m(/a/g);

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Now how would i grab "a", "b" , "c"? 
m(/abc?/g)

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I am basically trying to count how many total I have of "a", "b" "c".

So if I had a word "fileCapaber"
My count would be 4 with the "C" two "a's" and one "b" All I need is the regular expression to fetch those letters out of a word. thanks.

Replies are listed 'Best First'.
Re: Fetching 3 letters only
by thelenm (Vicar) on May 23, 2003 at 19:08 UTC
    Actually, you don't need a regular expression for this... use tr instead. 
    my $count = "fileCapaber" =~ tr/AaBbCc//;
print "Count is $count\n";

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    -- Mike

    --
    just,my${.02}

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Re: Fetching 3 letters only
by artist (Parson) on May 23, 2003 at 19:12 UTC 
    $_ = q(fileCapaber);
my $count = ($_ =~ y/abcABC/abcABC/);
print $count;

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    artist
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[d/l]
      Thanks. Actually I have several words to fetch so I need a reg expression to fetch the specific letters "a" "b" "c"
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        If you only want the total 

        my $s = 'fileCapaber';
my $count = () = $s =~ m[(a|b|c)]gi;
print $count;

4

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        but the tr/// solution above is easier and quicker.

        If you want the individual counts, then you could try this. 

        print 'Found: ', scalar( () = $s =~ m/($_)/ig), "'${_}'s\n" for qw[a b
+ c]

Found:  2 'a's
Found:  1 'b's
Found:  1 'c's

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        Examine what is said, not who speaks.
        "Efficiency is intelligent laziness." -David Dunham
        "When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller
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Re: Fetching 3 letters only
by hangmanto (Monk) on May 23, 2003 at 19:22 UTC
    This should fit your requirements. You need to modify the $word variable.

    Remember, when you need to count occurances, the hash is your friend. 

    use strict;

my $word = 'abcdefabcdeab';
my ( %counters, $total );
while ( $word =~ /([a-c])/gi )
{
    $counters{$1}++;
}

foreach my $letter ( sort keys %counters )
{
    print "\n$letter: " . $counters{$letter};
    $total += $counters{$letter};
}
print "\nTotal: $total";

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    Produces: 
    a: 3
b: 3
c: 2
Total: 8

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    I hope this helps.
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      Wow, Thanks for all the answers. I will print all of them and use for future reference. Thanks again!
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Re: Fetching 3 letters only
by BrowserUk (Patriarch) on May 23, 2003 at 19:09 UTC

    Erm... Is this m(/a/g); a Perl regex?

    Examine what is said, not who speaks.
    "Efficiency is intelligent laziness." -David Dunham
    "When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller
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[d/l]
      It most certainly is. It just requires a bit more than just an a to match though.

      Abigail

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        Right you are:) I was looking for what I wanted to see, instead of seeing what was there!

        Examine what is said, not who speaks.
        "Efficiency is intelligent laziness." -David Dunham
        "When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller
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