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Java Java Objects Delivering the MVP Applying a Discount Code

Daniel Gelabert
Daniel Gelabert
944 Points

May be a bug?

I write this code, and I think it is OK, but when I submit it for task 2 it says it does not pass task 1 anymore, and I come back to task 1, submit the exactly same code and it passes... What is wrong? Is my code wrong? Or is the website check wrong?

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) { //This is the part that I made for the task
    for (char c : discountCode.toCharArray()) {
      if (!Character.isLetter(c) || c!='$'){
        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"
    }

  }
}
samiff
samiff
31,206 Points

Hi Daniel,

You almost got it, but think about what the following logic in your code is doing:

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

Imagine we are passing the '$' character to your if statement there. Because the || operator is being used, only one side needs to be true for that exception to trigger. Character.isLetter('$') would evaluate to false because it's not a letter, but the ! in front would negate the false into a true. The second half containing the c!='$' wouldn't be considered at this point.

1 Answer

Daniel Gelabert
Daniel Gelabert
944 Points

Oh God you are right, I did a mistake there, thank you very much!