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Java Java Objects (Retired) Delivering the MVP Defaulting Parameters

Uncommented the code after comment, still not able to execute

Getting an error: "Did you uncomment the line after comment", even after removing the comment

Example.java
public class Example {

  public static void main(String[] args) {
    ShoppingCart cart = new ShoppingCart();
    Product pez = new Product("Cherry PEZ refill (12 pieces)");
    cart.addItem(pez, 5);
    /* Since a quantity of 1 is such a common argument when adding a product to the cart,
     * your fellow developers have asked you to make the following code work, as well as keeping
     * the ability to add a product and a quantity.
     */
    Product dispenser = new Product("Yoda PEZ dispenser");
    /* Uncomment the line following this comment,
       after adding a new method using method signatures,
       to solve their request in ShoppingCart.java
    */

     cart.addItem(dispenser);
  }

}
ShoppingCart.java
public class ShoppingCart {

  public void addItem(Product item){
  System.out.printf(" Adding %s to the cart", item.getName());
  }

  public void addItem(Product item, int quantity) {
    System.out.printf("Adding %d of %s to the cart.%n", quantity, item.getName());
    /* Other code omitted for clarity. Please imagine
       lots and lots of code here. Don't repeat it. 
    */
  }
}
Product.java
public class Product {
  /* Other code omitted for clarity, but you could imagine
     it would store price, options like size and color
  */
  private String mName;

  public Product(String name) {
      mName = name;
  }

  public String getName() {
      return mName;
  }
}

2 Answers

Hi Kumar,

The task here is to overload the addItem method so that it can be called more simply to just add a single item.

The addItem method is very complex - we can't see the code behind the scenes but it'll mnage database read/write and update web pages etc. We can't duplicate that code, but it must be run when an item is added. The comments say:

    /* Other code omitted for clarity. Please imagine
       lots and lots of code here. Don't repeat it. 
    */

The original method takes an item and a quantity. The new method just needs an item as it'll default the quantity to one. How to do this? You've correctly amended the method signature so that's done. But there's nothing in there to actually add an item.

How about using the code that's already written - we know that works, right?

public void addItem(Product item){
    addItem(item, 1);
}

To avoid repeating any code; use the original code. Just pass the item requested to the original method, inserting 1 as the quantity.

Hope that helps,

Steve.

Thanks for the reply Steve...got the logic...

No problem! That's an interesting challenge - with a very useful solution.