CODEWITHSUNDEEP
regex
Alexandra Diaconu
Alexandra Diaconu

Reputation: 21

Regex expression to invalidate numbers separated by comma

I have to make a regex expression to invalidate numbers which are separated by comma.

1_2_3 - valid

1_2_3,1_3 - invalid

What I have so far: ([1-9+_]*[1-9]*[^,]

Upvotes: 1

Views: 101

Answers (1)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 627607

You can use

^\d+(?:_\d+)*$

See the regex demo. Details:

  • ^ - start of string
  • \d+ - one or more digits
  • (?: - start of a non-capturing group:
    • _ - an underscore
    • \d+
  • )* - zero or more occurrences of the pattern sequences in the group
  • $ - end of string.

Note: in case the flavor is JavaScript, it is fine to use \d to match any ASCII digit and it is equal to [0-9]. If you need to match any number without leading zeros still accepting a 0, you may replace each \d with (?:0|[1-9]\d*) construct that matches a 0 or a digit other than 0 followed with any zero or more digits.

Upvotes: 1

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