What will be the regex for this type of string?

The regular expression should accept string like:V123456_123456_123456.

1. String must start with V.
2. Then any number of digits.
3. _(underscore) character followed by any number of digits.
4. Finally an _ character then any number of digits.

Answer 1

[Rik]

expr = 'V/d*_/d*_/d*';

Or, if 'any' actually means '1 or more':

expr = 'V/d+_/d+_/d+';