How to validate a user name with regex?

Question

This seems to match the rules I have defined, but I only starting learning regex tonight, so I am wondering if it is correct.

Rules:

• Usernames can cons

Answer 1

Your regex doesn't work. The hard part is the check for consecutive spaces/hyphens. You could use this one, which uses look-behind:

/^[a-zA-Z0-9][a-zA-Z0-9_\s\-]*[a-zA-Z0-9](?