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Question: So at your new Java job, you've written a brand new Shopping Cart system for the website. After some developers have used the objects you created for a while, they ask you to make it easier to add things to the cart.

Check out more instructions in Example.java. Once you implement their request, check your work, and you will pass the challenge.

Code:

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 this line after 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) {
    quantity = 1;
    System.out.printf("Adding %d of %s to the cart.%n", quantity, item.getName());
    /* Other code omitted for clarity */
  }
}

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;
  }
}

Answer 1 · 2015-01-15T03:31:51Z

January 15, 2015 3:31am

Hello, what you are being asked to do is create a method that adds only one item. Leave the initial method as is, so it should look something like

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 */
  }
public void addItem(Product addedItem) {
addItem(addedItem, 1);
}

Also, be unsure to uncomment the cart.addItem(dispenser); from the origional code.

Answer 2 · 2015-04-06T15:58:01Z

April 6, 2015 3:58pm

Example.java has a line of code that is commented out

    cart.addItem(dispenser);

If all you do is uncomment this line and check your work, you get a compiler error. We need to write a second addItem method that only takes one argument, rather than two.

So, in ShoppingCart.java, we can copy and paste the existing addItem method, but remove the second argument. We also need to change what is printed, because we know that we are Adding 1 of the item to the cart.

The output of your new addItem method must read

"Adding 1 of %s to the cart.\n"

Answer 3 · 2015-01-16T23:00:33Z

January 16, 2015 11:00pm

I passed with the solution as done above, with the addItem method with two parameters. But I also tried creating a new one parameter addItem method in the ShoppingCart class. I wonder why not use this?

Answer 4 · 2015-01-17T03:23:35Z

January 17, 2015 3:23am

I did this challenge a second time. First I tried just to just uncomment the "cart.addItem(dispenser);" in the Example class. But that had an error. So, I created another method signature for addItem,, that only had one parameter, in the ShoppingCart class. The "1" is a literal, so it doesn't count as a parameter. When I did that, it passed.

So, when I did the challenge the first time with "cart.addItem(dispenser);" in Example class, but it erred. When I had "cart.addItem(dispenser, 1);", it passed. I wonder why "cart.addItem(dispenser);" can't work, since it more closely matches the method signature?

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Devin Scheu

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Help With Java

4 Answers

Rob Bridges

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Rob Bridges

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daviddavis3

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