Lab-ZipcoderStore-HashMap

Store Lab

• Purpose - to understand HashMap, objects and data encapsulation.

• Objective - to create two type of maps

Part 1 - Equals & HashCode

By default, every Java object has an equals and a hashCode method. Java uses the object's address to calculate the hashCode. By default, two objects are equal if they have the same address. We don't want this. Two objects are equal if they are the same class and have the same values.

1. User
   1. Add an equals method to the User class. The equal method should return true only if the id and name of the user are the same. It return false otherwise.
   2. Add a hashCode method by calling Objects.hash() and gives it the id and name (e.g. Objects.hash(id, name))
2. Cart
   1. Add an equals and hashCode methods with IntelliJ shortcut
      1. Click Command + N and select equals and hashCode. Follow the wizard to generate the code.

Part 2 - ListMap

This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language

Part 1 - ListMap

In the test folder, there is a ProductTest with most of the tested commented out.

1. The first test testConstruction_WithNoParams checks to see if the Product class has an empty constructor. To test it, I created a new object with no parameter.
2. The second test testGetSetName checks to see if you can set and get the name of the product. In order to make this pass, I added a String field called name (line 5). Then I added a getter method getName (line 18-20) and a setter method setName(String name) (line 23-25).
3. The third test testConstruction_WithName checks if the Product class has a constructor that takes a String. Notice we can have more than one constructor. When I create a new Product with a string new Product("T-shirt"), I set that string to the field name so when I called getName, I get the string that I passed into the constructor.
4. Continue to uncomment the test and write the code to make it pass
5. For the product description, it should be in this format title (Color: color, Size: size)
   • ex: Hat (Color: Yellow, Size: LG)

Part 2 - Cart

A cart has an array of Product.

1. Open the CartTest and uncomment line 9-13. To make the test pass:
   • Create a new class named Cart
   • Create a new constructor that takes an array of Product
   • Run the test, it should pass
2. Create a getter for Product to make testGetProducts test pass
3. To make testGetSetDiscount test pass:
   • Create a new decimal field called discount
   • Create a getter and setter for the field
   • Run the test
4. To get getProductTotal tests to pass, you need add all the product prices together and return the result.
5. To get the total, you need to add the total of all the products minus the discount. For example, if a product costs $100, and the discount is 20% (0.20), then the total = 100 - (100 * 0.20) = 80

Part 3 - CreditCard

The goal of this exercise is to know how to create and test a class.

1. In the test folder, create a new test class called CreditCardTest
2. Create a new class called CreditCard
3. Create a test case to get and set the cardHolderName of the type String
   • Create getter and setter methods in the CreditCard class
   • Add a field called cardHolderName
4. Do the same for the following fields:
   • String number
   • int expiredMonth
   • int expiredYear
5. Create a getter and setter for each field
6. Create a test for getDescription
   • getDescription should return [cardHolderName] [last 4 digit of the number] [expiredMonth]/[expiredYear]
     • ex: Tia Mowry 4551 10/2019
7. Add a CreditCard field to the Cart class
   • Add a getter and setter for the creditCard field

Part 4 - Product as an ArrayList - BONUS

The goal of this exercise is to change the products array in the Cart class to an ArrayList.

1. In the CartTest, change the products array to an ArrayList

     ArrayList<Product> products = new ArrayList();
     products.add(new Product("Shirt", 15.01));
   

2. Add this test to the CartTest class

   @Test
   public void testAddToCard(){
       // Given
       ArrayList<Product> products = new ArrayList();
       Cart cart = new Cart(products);
   
       // When
       Product shirt = new Product("Shirt", 1.99);
       cart.addProduct(shirt);
   
       // Then
       double expectedTotal = 1.99;
       double actualTotal = cart.getProductTotal();
       Assert.assertEquals(expectedTotal, actualTotal, DELTA);
   }
   

   • Add a addProduct method to the Cart class
   • Run the test. It should pass.