CODEWITHSUNDEEP
regex
Kevin
Kevin

Reputation: 7309

Need a regular expression to match three character strings

I generally stay away from regular expressions because I seldom find a good use for them. But in this case, I don't think I have choice.

I need a regex for the following situation. I will be looking at three character strings. It will be a match if the first character is 1-9 or the letters o,n,d (lower or upper) AND the second character is 1,2 or 3 and the third character is 0-9.

Can anybody help me out?

Upvotes: 1

Views: 9959

Answers (6)

Greg
Greg

Reputation: 47164

[1-9ond][123][0-9]

Here's a useful place to test your RegEx.

Upvotes: 2

codebunny
codebunny

Reputation: 2899

Perl RegEx: /^[1-9ondOND][1-3][0-9]$/

^ at the start of the string;
$ at the end of the string.

Upvotes: 2

Suganthan Madhavan Pillai
Suganthan Madhavan Pillai

Reputation: 5655

A very late answer, but hope this will help

([1-9]|(?i)(o|n|d))[123][\d]

http://regex101.com/r/vE2jT1/1

Upvotes: 0

Blair Conrad
Blair Conrad

Reputation: 242100

[1-9ondOND][123][0-9]

I omitted the ^ and $ (beginning and end of string markers) because you said you'd have three-character strings, but there's no harm in including them, and they may improve speed, not that that'll be a big deal on such short input.

Of course, this assumes you're working in a language and locale where the uppercase equivalent of o, n, and d are O, N, and D. If not, you'll need to tell your regex interpreter to ignore case. The mechanism varies by language/framework.

For python, you'd use something like:

re.match('[1-9ond][123][0-9]', inputstring, re.IGNORECASE)

The re.match forces a match at the beginning of string, so you wouldn't need the ^ in any case.

Upvotes: 5

JaredPar
JaredPar

Reputation: 755457

Slight variation on a few other answers. Restrict the input to be exactly the matched text.


^[1-9ondOND][123][0-9]$

Upvotes: 9

Matthew Scharley
Matthew Scharley

Reputation: 132494

In a PREG-based system (most of them these days):

^(?:[1-9]|[ond])[1-3][0-9]$

Some systems require the start/end markers (PHP, Perl, but not .NET for instance), if yours does, it'd end up something like:

/^(?:[1-9]|[ond])[1-3][0-9]$/

Upvotes: -2

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