How to count the number of chars in a string

I needed to do this, and checked here and elsewhere for a method. Many had loops, some hashes , most multi-line.

I came up with (perhaps not exclusively, as was The Calculus!) this approch to counting the # of chars in a string.

This counts integers, for example:

 my $x = () = /\d\D*/g;
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The trick being /something(0-many in the set of !something)/as many as it finds..... ..so like, for letter A, <code> my $As = () = /A^A*/g

We dont need no stinking loops, hashes, etc..

Just an idear I had.. Probably some others had it to but I didn't find it in searches....

caveat- this may not work in dbg. If not, try it outside dbg and it should be OK.

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Re: How to count the number of chars in a string by choroba (Cardinal) on Jun 05, 2020 at 17:55 UTC
You don't need to match the non-digits when counting digits, the regex engine will happily skip over them. So, you can shorten the line to `my $count = () = /\d/g;` [download] If you need to count the characters in a tight loop, note that tr is faster than regex match: `my $count = tr/0-9//;` [download] Hashes are usually used when you're interested in frequencies of the individual characters. `my %freq; ++$freq{$_} for split //;` [download] `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l] [select]
Re: How to count the number of chars in a string by LanX (Saint) on Jun 05, 2020 at 17:36 UTC
You are not counting characters* but digits `\d` which might be followed by 0 or more non-numbers `\D` . Not sure why? I'd suggest better code if I new what your goal is. Edit The following example shows how to match (and consequently count) digits or any other character class. No need for weird negated character classes. `DB<6> x $_='12a3b';/\d/g 0 1 1 2 2 3 DB<7> x $_='12a3b';/[ab]/g 0 'a' 1 'b'` [download] Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery} ) Character_(computing) include letters, numerical digits, common punctuation marks (such as "." or "-"), and whitespace. Update In case you are only counting single characters and not combinations consider using `tr` instead, like described in Re: Some odd ambiguity in this regex	[reply] [d/l] [select]

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