title: formatting local phone numbers into international (knowing countries)
body: <p>I use an SMS API to send confirmation code to phone.<br />
  Its parameters requires me to set the visitors phone number format into international, for example +9912345678 instead of 012 345 678.<br />
  Is there a php class (without Composer) that would do it for me (could not find anything so far on GG), considering I know user's both country (from a select input) and number (from a text input) he submitted on the previous webpage?</p>