Question

This regular expression

/^\d{1,6}(?:\.\d{0,2})?$/

limits the user to only 6 digits.

1. How to make this regex work to allow any number of digits(no max limit)
2. How to make this regex optional

Answer 1

Assuming you just mean any number of digits followed by any single character followed by 2 digits, then use:

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

If 0 is ok, then:

/^\d*(?:.\d{0,2})?$/

I think you actually are trying to find money values (dollar and cents) which would likely be this instead:

/^\d*(?:\.\d{0,2})?$/