Overly Complex Phone Number Validator

Because phone numbers don't need to be simple, right?

1. Minimalist Phone Number

This phone number is so minimalist, it's almost invisible: 1

2. RegEx Golf Champion

You try to hit the ball into the hole with as few strokes as possible. In this case, you try to validate a phone number with as few characters as possible: \b\d+\b

3. Advanced Regular Expressions

This phone number uses the \d{3,4}\D{3}\d{3} pattern, because why not?

4. RegEx Ninja

The RegEx Ninja uses a combination of ^, \d{10,15}, and -$ to sneak up on its prey... er, phone number: