Regular Expression to match specific string

Question

RegEx has always been my Achilles' heel. I am writing web app, where user will input his identifier. I'm using RegexValidator to validate this input.

The identifier should be something like this:

TN-In-PL-KW-2012-1234

And this is how the identifier is built:

• first two letters are always TN
• followed by hyphen
• then two letters, that are either: In, Te, Yo or Et
• hyphen
• two uppercase letters
• another hyphen
• another two uppercase letters
• hyphen
• four digits, that are a year, so something between 1970 and 2012 (I can ignore that as long as there are 4 digits)
• hyphen
• ordinal number that can have from 1 to 4 digits

Please help me writing RegEx to match this identifier.

Answer 1

^TN-(In|Te|Yo|Et)-[A-Z]{2}-[A-Z]{2}-\d{4}-\d{1,4}$

Just as a comment, I recommend you Rubular if you want to improve your regex skills, it's a simple and practical page to have in mind when you need to work with regex

Answer 2

TN-(In|Te|Yo|Et)-([A-Z]{2}-){2}(19[7-9][0-9]|200[0-9]|201[0-2])-[0-9]{1,4}

Answer 3

TN-((In)|(Te)|(Yo)|(Et))-[A-Z]{2}-[A-Z]{2}-\d{4}-\d{1,4}