Javascript regex to match non repeating 9 digit number

Asked Aug 13 '20 at 19:49

Active Aug 13 '20 at 20:00

Viewed 618 times

I need to validate a string of number for non repeating numbers and a count match in JavaScript using regex

Use case :

Example :

123456789 should be valid

123456788 should be invalid - Same number not allowed twice

12345678 should be invalid - Doesn't have 9 numbers

1234567890 should be invalid - Has more than 9 numbers

I used below code to find a count match but don't know how to check for non repeating numbers

/(^\d{9}$)/

asked Aug 13 '20 at 19:49

1

Repeating number consecutive or repeating numbers in general? For example, is `123436789` valid (two 3's)? I'm assuming no duplicates allowed for full string – ctwheels Aug 13 '20 at 19:52
Have a look https://stackoverflow.com/questions/33656708/check-for-repeated-characters-in-a-string-javascript – Ihor Vyspiansky Aug 13 '20 at 19:52
6

You can use `^(?!\d*(\d)\d*\1)\d{9}$` assuming no duplicates for full string allowed. – ctwheels Aug 13 '20 at 19:53
3

For blocking adjacent repeats use `^(?!\d*(\d)\1)\d{9}$` – anubhava Aug 13 '20 at 19:55
2

See https://stackoverflow.com/questions/20205653/regex-to-find-numbers-with-unique-digits – Wiktor Stribiżew Aug 13 '20 at 20:00
3

Imo `^(?=\d{9}$)(?!.*(.).*\1)` with `RegExp.prototype.test()` is the best option. (in particular because too long strings fail before testing the negative lookahead). – Casimir et Hippolyte Aug 13 '20 at 20:05

0 Answers0