Java Java Objects Delivering the MVP Applying a Discount Code

java.lang.IllegalArgumentException: abc is not in uppercase at Order.normalizeDiscountCode(Order.java:24)

i am totally lost here. The compiler is pointing to a bug that i cant recognize, please help out.

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;
  }


  private String normalizeDiscountCode(String discountCode){
          this.discountCode=discountCode.toUpperCase();
          if(discountCode!=discountCode.toUpperCase()){
            throw new IllegalArgumentException (discountCode + " is not in uppercase");
          }
        return discountCode;

  }

  public String getDiscountCode() {
         return discountCode;
  }

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

Daniel Turato
PRO
Daniel Turato
Java Web Development Techdegree Graduate 30,100 Points

In the normalize method, you're setting this.discountCode to it's uppercase version whereas its only meant to be returned and set in the setter method. So take away the this.discount code and just do this and it will work:

private String normalizeDiscountCode(String discountCode) {
          return discountCode.toUpperCase();
}