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Java Java Objects Delivering the MVP Applying a Discount Code

Not sure how to add the '$' when normalizing the discount code

I tried an || in the if statement, but that did not work and I am not exactly sure where to go from here.

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 i : discountCode.toCharArray()){
      if (! Character.isLetter(i)){
        throw new IllegalArgumentException("Invalid discount code");
      }
    }
    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"
    }

  }
}

2 Answers

Kourosh Raeen
Kourosh Raeen
23,733 Points

Hi Sean - You can use &&. Check to see if the character is not a letter AND it is also not $, and in that case throw the exception.

I'm going to give you a hint which is not really the way to solve the challenge but it works well. (It's also considered slow in terms of computation what I have heard so far).

discountCode. matches("[a-zA-Z$]+")