Javascript - Matching a hyphen in regex

Question

I'm trying to match a string using regex (of which I am new to) but I can't get it to match.

These should be accepted:

• GT-00-TRE
• KK-10-HUH
• JU-05-OPR

These should not:

• HTH-00-AS
• HM-99-ASD
• NM-05-AK

So the pattern goes 2 letters, hyphen, 2 digits (between 00 and 11 inclusive), hyphen, 3 letters.

So far the best I can come up with is:

var thePattern = /^[a-z]{2}[-][00-11][-][a-z]{3}$/gi;

I can't help but feel that I'm pretty close.

Can anyone give me any pointers?

Thanks.

Answer 1

This should be what you need:

var thePattern = /^[a-z]{2}[-](0\d|1[0-1])[-][a-z]{3}$/gi;

In order to do a range 00-11, you have to say "(0 followed by 0-9) or (1 followed by 0 or 1)". This is because specifying a range within [] only works for single digits. Luckily your case is pretty simple, otherwise it could get quite complex to work around that.

Answer 2

Your regex is OK, but for one thing: the digits matching is a bit more complex

(0\d|10|11)

you want to match a zero followed by a digit ( \\d ) OR ( | ) a ten OR a eleven.

Something in square brackets represents just a single character in a range. [0-5] means any single digit between 0 and 5, [aq] means any lowercase letter from a to q. There's no such thing as [00-11] because it would require to work on more than one character at a time.