PPS Number Validation iOS Swift

Question

PPS number majorly used in Ireland. Its validation contains more calculation. How can we validate the PPS number in swift code?.

Answer 1

Below code is used to validate the PPS number in iOS Swift

  func isValidPPSN(_ ppsn: String) -> Bool {
    let ppsnRegEx = "^([0-9]{7})([A-Z]{1,2})$"
    let ppsnPred = NSPredicate(format:"SELF MATCHES %@", ppsnRegEx)
    return ppsnPred.evaluate(with: ppsn)
  }
  
  func validatePPSN(objInputValue: String) -> Bool {
    
    if !(isValidPPSN(objInputValue)) {
      return false
    }
    else {
      let numericPart = objInputValue[0 ..< 7]
      let checksumCharacter = objInputValue[numericPart.count ..< objInputValue.count]
      
      var multiplyingFactor = 8
      var sum = 0
      
      for i in numericPart {
        sum += (Int(String(i)) ?? 0) * multiplyingFactor
        multiplyingFactor -= 1
      }
      
      if checksumCharacter.count == 2 {
        sum += (Int(Character(checksumCharacter[1].uppercased()).asciiValue ?? 0) - 64) * 9
      }else{
        return false
      }
      
      let checksum = sum % 23;
      let asciiValue = Character(checksumCharacter[0].uppercased()).asciiValue ?? 0
      if ((checksum + 64) == asciiValue || (checksum == 0 && asciiValue == 87)) {
        return true
      } else {
        return false
      }
    }
  }
  

Call the function validatePPSN(objInputValue: String) pass PPS number in parameter its returns bool value number is valid or Not.