Question

I’d like to make a regular exp for C#. The 1st two letters are characters which are optional and then 4 digits which are mandatory.
as:

4584
0259
0015
G3227
G3277
G4018
G3737
G3737
G3277
GU4444
GU4444
G3277
G3277
G3988
C3737
G3227
G3227

Answer 1

I suggest this:

\b\p{L}{0,2}\d{4}\b

This would be for finding text like this in a larger string. If you want to validate a string instead, use

^\p{L}{0,2}\d{4}$