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Java Java Objects Delivering the MVP Applying a Discount Code

Michelle Huang
Michelle Huang
5,261 Points

I've been stuck here for a few days...Help please!

Can someone let me know why my normalizeDiscountCode method is not working and how I can change it?

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;
  }

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

  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"
    }

  }
}

1 Answer

JEFF CHAI
JEFF CHAI
7,564 Points

You can check it to this way by using for loop check on each character.

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