Java Java Objects Delivering the MVP Applying a Discount Code

Derek Doucette
Derek Doucette
872 Points

How does one call a new private method from the void applyDiscountCode method?

How does one call a new private method from the void applyDiscountCode method? Challenge Task 1. Java Objects. Delivering the MVP. Applying a Discount Code.

Maybe a more detailed breakdown of what is stated in the instructions?

Task:

Let's use your normalization skills to normalize a discount code for a Shopping Cart application. All codes should be upper cased, no matter what the user enters

For this first task, create a new private method named normalizeDiscountCode. It should take the discount code that is passed into the method and return the uppercase version. Call it from the current applyDiscountCode method and set this.discountCode to the result.

Thank you, Derek

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 = discountCode;
  }

  private String normalizeDiscountCode(String discountCode){
    this.discountCode = normalizeDiscountCode(discountCode);
    discountCode = discountCode.toUpperCase();
    return 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

Tonnie Fanadez
Tonnie Fanadez
UX Design Techdegree Graduate 22,767 Points

Hello Derek Doucette

Thanks for your question and providing the code.

You only need to create the private normalizeDiscountCode () method with a String return type. The method takes a String so you need to put a String in parenthesis. Then you need to call the String class method toUpperCase to convert the provided String inside the parentheses to Capital Letters. - String upperCaseDiscountCode = discountCode.toUpperCase () ** . This is the String value you need to return - **return upperCaseDiscountCode

Lastly inside applyDiscountCode iniatilize this.discountCode by calling the normalizeDiscountCode () method and supplying it with discount code.

My code example is below for your reference.

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

  private String normalizeDiscountCode (String discountCode){

//convertand return the discountCode as Upper Case
  return discountCode.toUpperCase();

  }

Cheers man