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Java Java Objects Delivering the MVP Applying a Discount Code

Adam VanDusen
Adam VanDusen
6,539 Points

Making this too hard?

I feel like this should work. I want false and not equal to throw the IAE but when I do this the site tells me that it can no longer get to return.

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

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

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

  }
  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);
  }
}
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"
    }

  }
}

2 Answers

Florian Tönjes
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Florian Tönjes
Full Stack JavaScript Techdegree Graduate 50,856 Points

Hi Adam,

right now your code will throw an Exception if the character is not a letter OR if it is not a dollar sign. You want to check if it is not a letter AND not a dollar sign.

Kind Regards, Florian

Adam VanDusen
Adam VanDusen
6,539 Points

OMG thank you! I was pulling my hair out on this one. :)