EasyValidation
Valid Username Checker
Write a regex that validates usernames: they must start with a letter, be 3-16 characters total, and contain only letters, digits, or underscores.
//
john_doe / a1 / 1john / valid_user123 / way_too_long_username_here / jo / _user
Test cases
- john_doeexpect match
- valid_user123expect match
- a1expect no match
- 1johnexpect no match
- way_too_long_username_hereexpect no match
- joexpect no match
- _userexpect no match