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Antony Hsu
4,377 PointsGot following error. Please help. Thanks. Q: What is wrong with method signatures for addItem?
./Example.java:31: error: method addItem in class ShoppingCart cannot be applied to given types; cart.addItem(dispenser); ^ required: Product,int found: Product reason: actual and formal argument lists differ in length 1 error
Below is the code:
public class Example {
private int mItemQty;
private String mName;
public void addItem(String itemDesc1) {
mName = itemDesc1;
}
public void addItem(String itemDesc, int itemQty) {
mName = itemDesc;
mItemQty += itemQty;
}
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);
}
}
public class Example {
private int mItemQty;
private String mName;
public void addItem(String itemDesc1) {
mName = itemDesc1;
}
public void addItem(String itemDesc, int itemQty) {
mName = itemDesc;
mItemQty += itemQty;
}
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);
}
}
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 */
}
}
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;
}
}
3 Answers
Kristen Law
16,244 PointsHi Antony! The reason you are receiving an error is because you defined your parameters in your addItem methods as Strings, but when you call the addItem method, you pass in Products.
Hope that helps!
Edit: Sorry, I read that wrong. Ignore what I wrote above.
The error that is occurring happens when you call cart.addItem(dispenser); in the main method of Example.java. If you look at the method definition of addItem in ShoppingCart.java:
public void addItem(Product item, int quantity)
you can see that you only have one method defined, and it must take two parameters. The error is occurring because you called addItem and only passed it one parameter. I haven't looked at the Code Challenge, so I'm not sure what it entails, but you might want to add an overloaded method to the ShoppingCart.java class that takes only one parameter, a Product.
Craig Dennis
Treehouse TeacherWe are just looking to default the addItem method with a quantity of 1. Here you should create a method (like you did) without the quantity parameter, and simply call the original addItem method but pass in 1 as the quantity. We covered something similar to this in the Method Signatures video if you would like to review.
Hope it helps!
Jess Sanders
12,086 PointsExample.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 the compiler error you posted in your question. 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.