Problem
I am trying to achieve a regular expression which matches [0-9]:[0-9] or [0-9].[0-9] or [0-9] or [0-9]: or [0-9].
What I have tried
/^\d?(\d+)?((\.|\:|\d)$|(\.|\:|\d)(\d+)?\d$)/ This regex which is satisfying my condition.
My optimized code
\d+[\.:]*\d* But this is accepting 2:2:. Actually it should not. Not able to solve this.
Your \d+[\.:]*\d* is not anchored and matches partial substrings matching the pattern. Also, it matches 11.....::::: like strings as [.:]* matches 0+ . or : chars.
You may use
^\d+(?:[.:]\d*)?$ See the regex demo.
Details
^ - start of string\d+ - 1+ digits(?: - start of a non-capturing group matching [.:] - one . or :\d* - 0+ digits)? - 1 or 0 times$ - end of string.
How about \d([:.]\d?)?? That should handle all the cases you mentioned.
Or \d+([:.]\d*?)? if you want to accept more than one digit in each number.
To only match if exact simply add ^ to the start and $ to the end of the regular expression. Example:
const regex = /^\d+([:.]\d*?)?$/ console.log(regex.test('2')) console.log(regex.test('2:')) console.log(regex.test('2.')) console.log(regex.test('2:3')) console.log(regex.test('2.3')) console.log(regex.test('12:23')) console.log(regex.test('23.34')) console.log(regex.test('2:3:4')) console.log(regex.test('2.3.4'))
Regex.test will return true if any part of the string matches. I've edited with a solution.\d*? lazy digit matching pattern makes it less efficient than with a greedy quantifier.2:2: is not getting matched completely, only the substring 2:2
To avoid this, just use the anchors ^ and $ like you used in the original pattern. Following is a working regex sample using your optimized regex with the anchors added - /^\d+[.:]?\d*$/, and here's a link to it https://regexr.com/47msc
^\d+(?:[.:]\d*)?$, see demo.