Question

I’m trying to build a regular expression for validating a SWTOR character name.

It needs to follow these rules:

1. Start with an uppercase letter
2. End with a lowercase letter
3. Only the first letter is uppercase, all other letters are lowercase
4. 3-15 characters in length
5. Can contain up to two apostrophes (‘)
6. Can contain up to one dash (-)
7. Apostrophes can’t be next to each other or a dash (No “Jo”e” or “Jo’-e”)
8. Entire name can only contain letters, apostrophes, and dashes.

So far, this is what I have which satisfies the first 4 rules and part of 5 and 6 and 8:

^([A-Z])([a-z'-]){1,13}([a-z])$

But my knowledge of regex is quite limited and I got stumped trying to figure out how to add the additional conditions around apostrophes and dashes.

Update: Added rule #8 for clarification per richardtallent’s feedback/answer.

Answer 1

Ok, let’s take these in turn:

First letter is uppercase:

^[A-Z]

Negative lookahead assertion, ensure there aren’t two dashes, any uppercase letters, two consecutive apostrophes, a dash and apostrophe together, or three apostrophes anywhere ahead:

(?!.*(-.*-|''|'-|-'|'.*'.*'|A-Z))

Then we need to actually match the middle characters, there must be between 1 and 13 of them:

[a-z'-]{1,13}

Finally, end with matching the lowercase letter:

[a-z]$

For the full expression, just combine the pieces:

^[A-Z](?!.*(-.*-|''|'-|-'|'.*'.*'|A-Z))[a-z'-]{1,13}[a-z]$

I’m assuming the .NET dialect of Regex since you didn’t specify.

Update: Added rule 8 and the part I missed from rule 7.