Java Java Objects Delivering the MVP Applying a Discount Code

Dina Hafez
Dina Hafez
10,288 Points

Not sure why it is not working.

Hello, I am not sure what I am doing wrong in my code. I am checking the string by using matches method and regex and inverting the result with not operator. Is there something that I am missing?

Order.java
public class Order {
  private String itemName;
  private int priceInCents;
  private String 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);
  }

  private String normalizeDiscountCode(String discountCode) {
    if (! discountCode.matches("[a-zA-Z$]")) {
      throw new IllegalArgumentException("Invalid discount code");
    }
    return discountCode.toUpperCase();
  }
}
Example.java
public class Example {

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

    Order order = new Order(
            "Yoda PEZ Dispenser",
            600);

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

    order.applyDiscountCode("$ale");
    order.getDiscountCode(); // $ALE


    try {
      // This will throw an exception because it contains numbers
      order.applyDiscountCode("ABC123");
    } catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"
    }
    try {
      // This will throw as well, because it contains a symbol.
      order.applyDiscountCode("w@w");
    }catch (IllegalArgumentException iae) {
      System.out.println(iae.getMessage());  // Prints "Invalid discount code"
    }

  }
}

1 Answer

KRIS NIKOLAISEN
PRO
KRIS NIKOLAISEN
Pro Student 51,735 Points

This stack overflow may help. Try adding a + to your regex.

if (! discountCode.matches("[a-zA-Z$]+")) {
Dina Hafez
Dina Hafez
10,288 Points

Yes! It worked. Thank you :)