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in reply to Some odd ambiguity in this regex

I'm trying to count digits in a scalar

Perhaps you could use tr///, see Quote Like Operators.

johngg@shiraz:~/perl/Monks$ perl -E '$_ = q{1223w3433.45+34}; say tr{0
+-9}{};'
12

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I hope this is of interest.

Cheers,

JohnGG

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Re^2: Some odd ambiguity in this regex
by AnomalousMonk (Archbishop) on Jun 05, 2020 at 19:50 UTC
    ... I'm trying to count digits in a scalar

    That's what the OP says, but the  /\d\D*/g regex suggests misterperl is trying to count occurrences of some kind of digit-group pattern. If that's the case, I can, offhand, think of some  s/// approaches (in the vein of a  tr/// operation) that would do the trick as well as the  m// approach that misterperl seems to favor: 

    c:\@Work\Perl\monks>perl -wMstrict -le
"$_ = '+++1223w3433.45+34***';
 ;;
 my $ndg;
 ;;
 $ndg =()= /\d\D*/g;
 print qq{A: $ndg digit grps.;  m// change unpossible '$_'};
 ;;
 $ndg = do { (my $r = $_) =~ s/\d\D*//g };
 print qq{B: $ndg digit grps.;  s/// string unchanged '$_'};
 ;;
 $ndg = s/(\d\D*)/$1/g;
 print qq{C: $ndg digit grps.;  s/// string unchanged '$_'};
 ;;
 $ndg = s/\d\D*//g;
 print qq{D: $ndg digit grps.;  s/// string CHANGED '$_'};
"
A: 12 digit grps.;  m// change unpossible '+++1223w3433.45+34***'
B: 12 digit grps.;  s/// string unchanged '+++1223w3433.45+34***'
C: 12 digit grps.;  s/// string unchanged '+++1223w3433.45+34***'
D: 12 digit grps.;  s/// string CHANGED '+++'

    [download]
    My own preference would be for the  m// approach.

    Give a man a fish:  <%-{-{-{-<

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