Java Java Objects Delivering the MVP Applying a Discount Code

Johannes Pedersen
Johannes Pedersen
1,004 Points

Hmmm, I called order.applyDiscountCode("abc") and I expected order.getDiscountCode to equal "ABC", but it was "abc"

Is the error the program gives me when i want to check my work. However, I dont see an issue with the code I wrote?

Help me figure it out please, ive been stuck here for quite a while now :P

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) {
    normalizeDiscountCode(discountCode);
    this.discountCode = discountCode;
  }

  private String normalizeDiscountCode(String discountCode){
    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

andren
andren
23,746 Points

The normalizeDiscountCode method returns a new string, it does not modify the string you call it on. So you have to assign the value it returns to this.discountCode for it to actually have a useful effect.

Like this:

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