phoneValidator static method

bool phoneValidator(
  1. String phone
)

Implementation

static bool phoneValidator(String phone) {
  //credit card if u wanna
  if (phone != "" && phone.contains(r"^(?:[+0][1-9])?[0-9]{10,12}$")) {
    // ^ beginning of a string
    // (?:[+0][1-9])? optionally match a + or 0 followed by a digit from 1 to 9
    // [0-9]{10,12} match 10 to 12 digits
    // $ end of the string

    return true;
  }
  return false;
}