|My friend is making windows form and he needs to vlidate a username which will be a minimum of 4 characters and maximum of 15 characters long. It will also allow hyphens and underscores as well as dots in the middle, but not at the start and neither at the end of the username. There may be no more than one hyphen, one underscore and one dot in a row
Examples of disallowed usernames:.
1236584 // not allow only numbers in username
aquib_ // means no symbols will be there at end
The username should not be only digits it should be either a mix of digits and alphabetical characters or it should be only alphabetic.
I hope this will be understood
I have got this regex:
which is not usefull enough