Trying to build a regular expression to check pattern

Question

a) Start and end with a number
b) Hyphen should start and end with a number
c) Comma should start and end with a number
d) Range of number should be from 1-31

Answer 1

An optimal Regex for this topic could be:

^(?'int'[1-2]?[1-9]|3[01])((,\g'int')|(-\g'int'(?=$|,)))*$

demo