REGEX To accept numbers separated by commas, but number range is 0-32767

Question

I need to write a regular expression for taking input like this

23,456,22,1,32767

i.e.

No commas allowed at the start or end.
Spaces may come before and/or start of comma for e.g. 23, 45,56 ,67 etc.
Ranges of each number should be 0-32767.

Currently I am using regular expression like this [0-9]+(,[0-9]+)*.

This allows for numbers separated by commas only ( not allowing spaces at all), and it does not check for the range of number.

You don't want to check the number range with regex, it will be relay unreadable — stema, Jun 07 '11 at 07:19
http://www.codinghorror.com/blog/2008/06/regular-expressions-now-you-have-two-problems.html — johnsyweb, Jun 07 '11 at 07:31

Mark Byers · Accepted Answer · 2011-06-07T07:27:30.613

16

It's probably wise to do it in two steps. First check that the range is 0-99999:

^[0-9]{1,5}( *, *[0-9]{1,5})*$

Then parse the string to a list of integers using a general purpose programming language and check that x <= 32767 for each integer x.

edited Jun 07 '11 at 07:27

answered Jun 07 '11 at 07:22

Mark Byers

811,555
193
1,581
1,452

1

+1, but you might want to add `\s*` around the comma to allow for spaces as Basmah asked. – Tim Pietzcker Jun 07 '11 at 07:26
"\s*" or " *"? The question seems very unclear on this point. – Mark Byers Jun 07 '11 at 07:28
Thanks Mark ! This was of help! – Basmah Jun 07 '11 at 11:21
Mark, would you please tell me the regex for th to write a regular expression for taking input like this 23,456,22,1,32767 i.e. 1.No commas allowed at the start or end. 2.Spaces may come before and/or start of comma for e.g. 23, 45,56 ,67 etc.e following – Basmah Jun 07 '11 at 11:24
what should I change in this just to accept numbers separated by commas and no spaces in between? – Sep 15 '16 at 03:58
how to make them non repeating – Mayur Dec 08 '16 at 17:51

Tim Pietzcker · Answer 2 · 2011-06-07T07:30:38.260

You can validate a number range with a regex, but since you need to look at the textual representation of numbers, the regex will be hard to read:

0*(?:3276[0-7]|327[0-5][0-9]|32[0-6][0-9]{2}|3[01][0-9]{3}|[12][0-9]{4}|[1-9][0-9]{1,3}|[0-9])

matches an integer between 0 and 32767, with optional leading zeroes.

So your entire regex would be

^0*(?:3276[0-7]|327[0-5][0-9]|32[0-6][0-9]{2}|3[01][0-9]{3}|[12][0-9]{4}|[1-9][0-9]{1,3}|[0-9])(?: *, *0*(?:3276[0-7]|327[0-5][0-9]|32[0-6][0-9]{2}|3[01][0-9]{3}|[12][0-9]{4}|[1-9][0-9]{1,3}|[0-9]))*$

Now imagine you inherit that regex from a co-worker who has left your company years ago...Have fun :)

Therefore, take Mark's advice.

_{This answer is intended purely for educational purposes and does not constitute a recommendation to use a regex in this case.}

REGEX To accept numbers separated by commas, but number range is 0-32767

2 Answers2