Regex match one of two words

Question

I have an input that can have only 2 values apple or banana. What regular expression can I use to ensure that either of the two words was submitted?

Answer 1

This will do:

/^(apple|banana)$/

to exclude from captured strings (e.g. $1,$2):

(?:apple|banana)

Answer 2

There are different regex engines but I think most of them will work with this:

apple|banana