Lock Phone Number With +62

main.js

const numbers = [
  "+6285123",
  "6285123",
  "085123",
  "85123",
];

const lockPhoneId = (number) => {
  let _number = number.toString().split('');

  // remove "+"
  if (_number[0] == '+') _number = _number.filter((_, i) => i > 0);
  // remove "0"
  if (_number[0] == '0') _number = _number.filter((_, i) => i > 0);
  // remove "62"
  if (`${_number[0]}${_number[1]}` == '62') _number = _number.filter((_, i) => i > 1);

  return _number.join('');
}

numbers.forEach(number => console.log(lockPhoneId(number)))

// todo: create with other approach, ex: regex