Week 3 - Data Structures & Testing 

Collections

Generics

Enums

Stream APIs

Unit Testing with JUnit

Debugging in Java

Practice

Assignment

• Teachers

Back end Track

Week 3 Assignment

Task 1 - Pizza Order

We will build a small model for pizza ordering. An order holds a list of pizzas. Each pizza has a size and a list of toppings. The model can calculate the total price of an order and print a receipt.

Requirements

1. Size enum where each value carries a base price in euros:
   • SMALL → €6.00, MEDIUM → €9.00, LARGE → €12.00
   • Create a function getBasePrice() to return the size price.
2. Topping enum where each value carries a price:
   • CHEESE → €1.00, MUSHROOMS → €1.50, PEPPERONI → €2.00, OLIVES → €1.00, PINEAPPLE → €1.50
   • Create a function getPrice() to return the topping price.
3. Pizza class:
   • Members:
     • Pizza size
     • List of toppings
   • A constructor that takes both size and the list of toppings
   • Public methods:
     • getTotalPrice() returning the size's base price plus all topping prices
     • toString() returning MEDIUM pizza with [CHEESE, MUSHROOMS] - €11.50
4. Order class:
   • Members:
     • List of pizzas (Starts empty)
   • Public methods:
     • addPizza(Pizza pizza) - Adds a new pizza to the order.
     • getTotalPrice() returning the sum of all pizza prices
     • printReceipt() printing one line per pizza followed by a total line
5. Main - create an order with at least three pizzas of different sizes and toppings, then print the receipt.

Expected output

=== Receipt ===
MEDIUM pizza with [CHEESE, MUSHROOMS] - €11.50
LARGE pizza with [PEPPERONI, OLIVES, CHEESE] - €16.00
SMALL pizza with [PINEAPPLE] - €7.50
---------------
Total: €35.00

Hint: enums can carry data

Task 2 - Generic Cache

Caching is the process of storing temporary copies of frequently accessed data in a fast, easy-to-reach location (the "cache"). For example, fetching something from the database once and storing it in the memory to fast access.

In this task, we will build a reusable in-memory cache. The class is generic, so the caller decides the value type when creating an instance. In addition, we will be covering our class with unit tests.

Requirements

Cache<T> - backed internally by a HashMap. Implement these methods:

• put(String key, T value) - Add a new item to the cache
• public T get(String key) - Fetches an item from the cache. The item may not be in the cache.
• T remove(String key) - Remove an item from the cache and return it.
• int size() - Returns the number of items in the cache.
• void clear() - Removes all items from the cache
• Add unit tests to each of the functions above
• In the main function create two different caches with two different types: String and Double . Call a few methods on those objects.

Examples

Cache<String> stringCache = new Cache<String>();
stringCache.put("name", "HackYourFuture");
stringCache.get("name"); // -> "HackYourFuture"
stringCache.get("city"); // -> null

Cache<Integer> numberCache = new Cache<Integer>();
numberCache.put("c1", 12345);
numberCache.put("c2", 54321);
numberCache.size(); // -> 2
numberCache.remove("c1");
numberCache.get("c1"); // -> null

Submission

Follow the Assignment submission guide to learn how to submit the assignment

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