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Java Java Objects Delivering the MVP Applying a Discount Code

Iulian Cristea
Iulian Cristea
901 Points

Let's use your normalization skills to normalize a discount code for a Shopping Cart application. All codes should be up

I recive the following error message " Bummer! Hmmm, I called order.applyDiscountCode("abc") and I expected order.getDiscountCode to equal "ABC", but it was "abc"" and in Output is 'ABC'. Can you tell e what is the probleme?

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 txt) {
    return txt.toUpperCase();
  }

  public String getItemName() {
    return itemName;
  }

  public int getPriceInCents() {
    return priceInCents;
  }

  public String getDiscountCode() {
    return discountCode;
  }

  public void applyDiscountCode(String discountCode) {
    this.discountCode = discountCode;
    System.out.print(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"
    }

  }
}
David Moody
David Moody
19,302 Points

Here is your code:

public void applyDiscountCode(String discountCode) { this.discountCode = discountCode; System.out.print(normalizeDiscountCode(discountCode)); }

Changes you should make:

First, don't print. When you do print, you typically printf or println. But in this case, don't print.

Second, set this.discountCode equal to the call of normalizeDiscountCode and pass in discountCode. Like this:

public void applyDiscountCode(String discountCode) { this.discountCode = normalizeDiscountCode(discountCode); }