Version number validation

Question

My product version number is of the format "P.Q.R", where P, Q, R are digits. The valid inputs are "P", "P.Q", "P.Q.R".

I wrote regular expression performing an OR operation.

(^\d+$) | (^\d+.\d+$) | (^\d+.\d+.\d$)

Is there much simpler way to write using JavaScript ?

Answer 1

The following regex should work:

^\d+(\.\d+){0,2}$

The \d+ indicates any number of digits. The (\.\d+) indicates a dot followed by any number of digits, and the {0,2} means the last group can be repeated 0-2 times. The ^ and $ indicate the start and end of the string, so the regex will match the whole thing.