Regular Expression Match to test for a valid year

Question

Given a value I want to validate it to check if it is a valid year. My criteria is simple where the value should be an integer with 4 characters. I know this is

Answer 1

Use;

^(19|[2-9][0-9])\d{2}$ 

for years 1900 - 9999.

No need to worry for 9999 and onwards - A.I. will be doing all programming by then !!! Hehehehe

You can test your regex at https://regex101.com/

Also more info about non-capturing groups ( mentioned in one the comments above ) here http://www.manifold.net/doc/radian/why_do_non-capture_groups_exist_.htm