tungvn

/*
Before Septemper 15 2018, Vietnam has phone number start with 09*, 01(2|6|8|9).
After that, the phone number can start with 03, 05, 07 or 08.
So this function provide a way to validate the input number is a Vietnamese phone number
*/

function isVietnamesePhoneNumber(number) {
  return /(03|05|07|08|09|01[2|6|8|9])+([0-9]{8})\b/.test(number);
}