Regex for Comma delimited list

Question

What is the regular expression to validate a comma delimited list like this one   12365  45236  458  1  99996332

User · Answer

This one will reject extraneous commas at the start or end of the line, if that's important to you.

((, )?(^)?(possible|value|patterns))*

Replace possible|value|patterns with a regex that matches your allowed values.

User · Answer

You might want to specify language just to be safe  but    d        d      ought to work

User · Answer

In JavaScript  use split to help out  and catch any negative digits as well    -1 2 -3  match   -  d     s -  d      0  split            -1    2    -3      may need trimming if digits are space-separated

User · Answer

It depends a bit on your exact requirements  I m assuming  all numbers  any length  numbers cannot have leading zeros nor contain commas or decimal points  individual numbers always separated by a comma then a space  and the last number does NOT have a comma and space after it  Any of these being wrong would simplify the solution       1-9  0-9         1-9  0-9    Here s how I built that mentally    0-9   any digit   1-9  0-9    leading non-zero digit followed by any number of digits  1-9  0-9    as above  followed by a comma  1-9  0-9       as above  followed by a space   1-9  0-9         as above  repeated 0 or more times   1-9  0-9        1-9  0-9    as above  with a final number that doesn t have a comma

User · Answer

This regex extracts an element from a comma separated list  regardless of contents                  If you just replace the comma with something else  it should work for any delimiter

User · Answer

I had a slightly different requirement  to parse an encoded dictionary hashtable with escaped commas  like this    1 This is something  2 This is something  with an escaped comma  3 This is something else    I think this is an elegant solution  with a trick that avoids a lot of regex complexity   if  string IsNullOrEmpty encodedValues         return null    else       var retVal   new Dictionary lt int  string gt         var reFields   new Regex     0-9        A-Za-z0-9 s                  foreach  Match match in reFields Matches encodedValues                       var id   match Groups 1  Value          var value   match Groups 2  Value          retVal int Parse id     value Replace                       return retVal      I think it can be adapted to the original question with an expression like     0-9     s   and parse on Groups 0    I hope it s helpful to somebody and thanks for the tips on getting it close to there  especially Asaph

User · Answer

d        d

User · Answer

Match duplicate comma-delimited items      lt                1            Reference   This regex can be used to split the values of a comma delimitted list  List elements may be quoted  unquoted or empty  Commas inside a pair of quotation marks are not matched           lt          s                                      s            Reference

User · Answer

i used this for a list of items that had to be alphanumeric without underscores at the front of each item       0-9a-zA-Z  0-9a-zA-Z         0-9a-zA-Z  0-9a-zA-Z

User · Answer

The following will match any comma delimited word digit space combination

User · Answer

I suggest you to do in the following way     d     s  d      which would work for a list containing 1 or more elements

[regex] Regex for Comma delimited list

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