Regular expression for 1-31

Question

I'd like to make a reglar expression which checks date digit e.g. 1 through 31. I think it has three patterns : [0-9], [12][0-9], 3[01].

But I don't know how to make them as one regex with |(or) operator.

Anybody has idea for this?

You know you need to use the `|` operator, but have you tried anything with it yourself? — Joe Sewell, Aug 27 '18 at 15:05
I did it on the https://regex101.com/ page. But it didn't work. — user7194131, Aug 27 '18 at 15:08
Download Expresso, it's a free tool will help you with the Regex. Your date digit it's not clear did you mean something like ddmmyyyy ? — Cédric Boivin, Aug 27 '18 at 15:15

Shai · Answer 1 · 2018-08-27T15:16:29.553

1

Updated:

([0-2][0-9]|(3)[0-1])

Hope this answer your question

edited Aug 27 '18 at 15:16

answered Aug 27 '18 at 15:06

Shai

I tried to write your expression on the regex101.com page and try 32. But it said two matches. – user7194131 Aug 27 '18 at 15:10
Thanks. it works. – user7194131 Aug 27 '18 at 15:20

score 1 · Answer 2 · answered Aug 27 '18 at 15:12

1

What you need is alternation and a group to make the pattern local. Just use a | within the capture group (a|b) or non-capturing group (?:a|b):

([1-9]|[12][0-9]|3[01])

answered Aug 27 '18 at 15:12

Thomas Ayoub

2 Answers2