Regex to match one of lengths, but nothing in between

Question

When I want to test if input string is at least length 10 and at most length 13, I use this pattern: [0-9]{10,13}

But how would you test if the string length is 10 or 13 and nothing in between?

EDIT: I see two dominant solutions:

1) Using length1 OR length2 2) Using length1 + optional characters of (length2 - length1)

Just wondering: are there any performance differences between the two?

Well, it's hard to define a search string for a question like this. — Arman Bimatov, Nov 03 '13 at 20:53
@ArmanBimatov you might check this [question](http://stackoverflow.com/questions/3470990/is-micro-optimization-worth-the-time/3471356#3471356) out and this [tweet](https://twitter.com/ircmaxell/status/370993140628344833) :) — HamZa, Nov 03 '13 at 21:30
Not quite the same question. The nominated duplicate asks whether there is another solution. This question asks about the performance difference between two solutions. — Wayne Conrad, Mar 22 '14 at 12:26

score 2 · Accepted Answer · answered Nov 03 '13 at 20:56

2

Another option would be

^[0-9]{10}(?:[0-9]{3})?$

answered Nov 03 '13 at 20:56

jkshah

Don't rip off the solution from a duplicate, you have the power to close it as duplicate :) – HamZa Nov 03 '13 at 20:58
@HamZa Sorry to say but I didn't even see duplicate post or ans. I was trying to construct my solution. If you believe it's ok, if you not still it's ok. It may just be coincident. the other 4 ans are similar, in-fact same, that doesn't mean they have copied from one another! – jkshah Nov 03 '13 at 21:01
I removed my answer since all people overflowed the question with almost the same answer, you've come with one that's not similar and I find it really creative if you found it by your own. But don't forget to "clean up" stackoverflow. Well you're not "forced" anyway, just suggesting ... – HamZa Nov 03 '13 at 21:04
@HamZa Had I seen that duplicate, I would surely have removed my ans and posted the ans in comment. Now that nobody else has posted this option, I would like to retain it. I do not intend to flood SO with rep rip-off answers! – jkshah Nov 03 '13 at 21:09

bukart · Answer 2 · 2013-11-04T16:11:28.037

1

use this expression ^((?:\d{3}){3,4}\d)$

edited Nov 04 '13 at 16:11

answered Nov 03 '13 at 20:52

bukart

Actually, if you test it, it will return true for 12345678901 (which is 11 characters) – Arman Bimatov Nov 03 '13 at 20:56
fixed it, please try again – bukart Nov 03 '13 at 21:01

2 Answers2