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Java Java Objects (Retired) Delivering the MVP Defaulting Parameters

Christopher Harris
Christopher Harris
1,166 Points

Help on Task

if you preview the code it will have the right output so, where is my problem ?

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, 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. 
    */
  }
  public void addItem(Product item){
       System.out.printf("Add %d of %s to the cart.%n", 1, item.getName());
    } 
}
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;
  }
}

1 Answer

Benjamin Barslev Nielsen
Benjamin Barslev Nielsen
18,958 Points

When I try to solve the task with your implementation I succeed, but I would expect it to fail, since you duplicate the logic of adding an item. The idea is to use the already defined addItem, such that you don't have to write the same code multiple places:

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

In this way you don't have to worry about what addItem does, and if you need to make changes to addItem, it is only one place, you need to do it.

Christopher Harris
Christopher Harris
1,166 Points

hahah made a bit of a lash of that thanks :)