how to match specific combination of 2 letters with regex

Question

given this set of letters

xx | af | an | bf | bn | cf | cn

how can I see if, given two characters, they match against one of the above?

I could easily hardcode the solution with a switch case, but I think regex is a more elegant solution.

Answer 1

You basically wrote the regex yourself:

xx|af|an|bf|bn|cf|cn

Answer 2

You wrote the regular expression yourself as stated previously, you could simplify it to...

var re = /xx|[abc][fn]/

Answer 3

Try this:

^(xx|af|an|bf|bn|cf|cn)$

xx  => Correct
af  => Correct
aff => Incorrect
kk  => Incorrect

Live demo