title: How do I check string in this format: +xxx-yyyy-zzzz?
body: <p>X, y, z are all numbers. Beside knowing how to check if the string is 14 chars long, I don't want to iterate each character and check if the char matches [0-9].</p>
  
  <p>Are there smarter ways? No regex pls.... I'm scared of it.</p>