Java Java Objects Delivering the MVP Applying a Discount Code

help me with this problem.

I am not getting this.

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

Steven Parker
Steven Parker
177,482 Points

You've got the right idea, but to check if two things are not true, you would combine the expressions with AND instead of OR:

      if ( !Character.isLetter(ch) && ch != '$' ) {

You could also test if either condition is true (using OR), and then negate the result:

      if ( !(Character.isLetter(ch) || ch == '$') ) {

It,s still not working.

Steven Parker
Steven Parker
177,482 Points

Both of those work for me if a paste your code into the challenge and then replace that line with one of them. Maybe you accidentally changed something else? If you still have trouble, you may need to repost the entire code.