How to make credit card (xxxx-xxxx-xxxx) type text in swift

Question

I am trying to create credit card type text with following code, but not able to do that, is there any way to do?

func textField(textField: UITextFiel         


        

Answer 1

Below logic implements simple 16 digits credit card formatting with spaces.

Edit: Code adjusted for Swift 4/5

Step 1: Create an action for for credit card textfield

self.txtFieldCreditCardNumber.addTarget(self, action: #selector(didChangeText(textField:)), for: .editingChanged)

Step 2: Call a method from this selector method of textfield that will do the formatting

@objc func didChangeText(textField:UITextField) {
    textField.text = self.modifyCreditCardString(creditCardString: textField.text!)
}

Step 3: Implement the method "modifyCreditCardString"

func modifyCreditCardString(creditCardString : String) -> String {
     let trimmedString = creditCardString.components(separatedBy: .whitespaces).joined()

     let arrOfCharacters = Array(trimmedString)
     var modifiedCreditCardString = ""

     if(arrOfCharacters.count > 0) {
         for i in 0...arrOfCharacters.count-1 {
             modifiedCreditCardString.append(arrOfCharacters[i])
             if((i+1) % 4 == 0 && i+1 != arrOfCharacters.count){
                 modifiedCreditCardString.append(" ")
             }
         }
     }
     return modifiedCreditCardString
 }

Step 4: Implement the delegate of UITextField, which will restrict the card numbers to 16 characters. 19 = 16 + 3 (1 spaces after each 4 digits)

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
     let newLength = (textField.text ?? "").count + string.count - range.length
     if(textField == txtFieldCreditCardNumber) {
         return newLength <= 19
     }
     return true
}

Hope this will help. Thanks