Regular expression to match phone number?

Question

I want to match a phone number that can have letters and an optional hyphen:

• This is valid: 333-WELL
• This is also valid: 4URGENT

Answer 1

Thank you Heath Hunnicutt for his alternation operator answer as well as showing me an example.

Based on his advice, here's my answer:

[A-Z0-9]{7}|[A-Z0-9][A-Z0-9-]{7}

Note: I tested my regex here. (Just including this for reference)