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Java Java Objects Delivering the MVP Applying a Discount Code

Carlo Antonio Bilbao
Carlo Antonio Bilbao
24,113 Points

Not sure why I'm getting this error...

Not sure what error is in line 9...

public class Order {
  private String itemName;
  private int priceInCents;
  private String discountCode;

  private String normalizeDiscountCode(String discountCode) {
    for (char letter : discountCode.toCharArray()) {
      if (! Character.isLetter(letter) || !discountCode.contains("$")) {
        throw new IllegalArgumentException("Invalid discount code");
    this.discountCode = discountCode.toUpperCase();
    return this.discountCode;

  public Order(String itemName, int priceInCents) {
    this.itemName = itemName;
    this.priceInCents = priceInCents;

  public String getItemName() {
    return itemName;

  public int getPriceInCents() {
    return priceInCents;

  public String getDiscountCode() {
    return discountCode;

  public void applyDiscountCode(String discountCode) {
    this.discountCode = normalizeDiscountCode(discountCode);
public class Example {

  public static void main(String[] args) {
    // This is here just for example use cases.

    Order order = new Order(
            "Yoda PEZ Dispenser",

    // These are valid.  They are letters and the $ character only
    order.getDiscountCode(); // ABC

    order.getDiscountCode(); // $ALE

    try {
      // This will throw an exception because it contains numbers
    } catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"
    try {
      // This will throw as well, because it contains a symbol.
    }catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"

23,759 Points

What error message are you getting?

1 Answer

Alex Bratkovskij
Alex Bratkovskij
5,329 Points

Heya Carlo,

if (! Character.isLetter(letter) || !discountCode.contains("$")) {

For the reasons that I do not know, OR doesn't like double denial, so I would suggest you to wrap them under one bracket and then your code will execute.

like so:

if (! (Character.isLetter(letter) || discountCode.contains("$"))){

Bare in mind that although this code will execute, you will not get task complete cuz discountCode.conains("$") does let through this : $@ving$ . Try using a letter and checking if it's equal to $, since you already flipping through them ;)

Good Luck!