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Java Java Objects Delivering the MVP Applying a Discount Code

David Park
David Park
1,953 Points

task 1 not passing when task 2 does

i put in my code for task 2 (throw exception when not a letter or '$') but now it doesnt accept what i had for task 1 (convert discountcode to upper case). help please

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

David Park
David Park
1,953 Points
    for (char letter : discountCode.toCharArray()) {
      if (!Character.isLetter(letter) || letter != '$') {
        throw new IllegalArgumentException("Invalid discount code.");
      }
    }
    return discountCode.toUpperCase();
  }
Anders Björkland
Anders Björkland
7,481 Points

Hi David!
Even though it says you don't pass task 1 anymore, you are actually at a problem with task 2.
You want both cases in your if-statement to be true to cast an exception; that is, when a character is not a letter, and it is not a $-character, then throw an exception.
Otherwise, as it stands right now, you will throw an exception if the character is not a letter ($ is not a letter), or if the character is not a $ (a letter is not $). So you would throw exceptions everytime you check a character since it can't be a letter and a $ at the same time.
Does it make sense? Hope you now know how to remedy your if-statement.