Regex for matching any number between 0 to 100?

Question

I need a regex to match any number between 0 to 100 including decimal numbers example: my expression should match 1,2,2.3 ,40,40.12 ,100,100.00 like this ..thanks in advance?

Would't be easier match a number and than compare it to 0 and 100? — Matteo, Aug 31 '12 at 11:12
see http://stackoverflow.com/questions/11011674/how-to-match-a-number-which-is-less-than-or-equal-to-100 — Fredrik Pihl, Aug 31 '12 at 11:14

score 2 · Answer 1 · answered Aug 31 '12 at 11:21

Assuming you have to allow for a leading sign, you are best off writing

if ( /(?<![-+.\d])([-+]?\d+(?:\.\d*)?(?![-+.\d])/ and $1 >= 0 and $1 <= 100 ) { .. }

But if you are forced into using a regex, then you need

if ( /(?<![-+.\d])(([-+]?(?:100|\d\d)(?:\.\d*)?(?![-+.\d])/ ) { .. }

These pattern may well be more complex than necessary because they allow for the number appearing anywhere in the string. If you are simply checking an entire string to see if it matches the criteria then it could be much shorter

Your regex `/(?<![-+.\d])(([-+]?(?:100|\d\d)(?:\.\d*)?(?![-+.\d])/` is incorrect. Even after I balanced the parentheses, it behaves incorrectly. — protist, Oct 04 '12 at 09:04

Hans Keﬆing · Answer 2 · 2012-08-31T17:26:58.363

0

This would work:

(100(\.0+))|([0-9]{1,2}(\.[0-9]+)?)

match either "100" (with optional dot plus one or more zeroes) or one or two digits, optionally followed by a dot and at least one digit.

edited Aug 31 '12 at 17:26

answered Aug 31 '12 at 11:14

Hans Keﬆing

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That matches numbers 100<=x<101 – justintime Aug 31 '12 at 14:37
@justintime - should be fixed now. Good catch. – Hans Keﬆing Aug 31 '12 at 17:27
This will match `1213215252` as `12 13 21 52 52`. – protist Oct 04 '12 at 08:59

protist · Answer 3 · 2012-10-04T09:00:19.860

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EDITED!!!

This problem was much more difficult than I initially realized. With some amount of effort, I have produced a new regex that is without error. Enjoy.

/(?<!\d)(?<!\.)(100(?:(?!\.)|(?:\.0*+|\.))(?=\D)|[0-9]?[0-9](?:\.|\.[0-9]*+)?(?=[\D]))/

This pattern will capture in $1

edited Oct 04 '12 at 09:00

answered Sep 03 '12 at 13:11

protist

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this will match `199.9999999` which is more than `100` – Toto Oct 03 '12 at 12:02
M42: I fixed the regex, please retract. :) – protist Oct 04 '12 at 08:56

Regex for matching any number between 0 to 100?

3 Answers3