Initialization Lab 1

Objectives

1. In this lab students will practice writing and using constructors
2. After this lab students should be able to produce enumerated types.
3. This lab introduces the practice of writing unit tests for code being developed.

Overview

This lab introduces constructors and enumerated types.

Unit Test

You are expected to write unit tests for the getColor method in this lab. Be sure to test that it returns the same color that was set in the constructor.

Remember to use Test Driven Development: create stubs of your methods and write your tests first, confirm that they run fail the tests, then implement your methods so that they pass the tests.

Instructions

For this lab, create a java file called InitializationLab1.Java

Part one = new Part();

1. In initialization.lab1 package create two classes, BoringThing and ColorfulThing
2. Create a constructor for ColorfulThing that takes one String as a parameter and stores it as an instance variable.
3. Provide a getColor method for ColorfulThing
4. Create the InitializationLab1 class and add a main method.
5. In main declare and instantiate five BoringThings and five ColorfulThings (pick any colors you like).
6. Print out each ColorfulThing's color.
7. Try creating another ColorfulThing using a default (no-argument) constructor. Notice that this causes an error.

public enum Part {II;}

Letting a user specify any string and blindly assuming it's a color is a bit naïve. Let's specify what colors of ColorfulThings are available.

1. Add an enumerated type called Color to ColorfulThing and give it at least three options
2. Refactor the ColorfulThing constructor and class to use the new enumerated type. Don't forget to refactor the getter you created earlier.
3. Adjust your main method to use the new enumerated type as well.
4. Run your program to make sure the new enumerated type works.

Initialization Lab 2

Objectives

1. In this lab students will practice overloading constructors and initializing objects based on constructor arguments.
2. After this lab students should be comfortable manipulating instance variables in constructors and other object methods.

Overview

This lab focuses on initializing objects using constructors and overloading constructors. It also introduces the use of arrays as arguments and instance variables.

Unit Test

You are expected to write unit tests for your code in this lab. Be sure to test the behavior of ThingContainer in multiple scenarios, including testing the add method when the `ThingContainer is or is not full. You are responsible for determining which other methods need to be tested and how to test them. Remember to practice Test Driven Development as you work on this lab.

Instructions

For this lab, use the java file called InitializationLab2.Java. Import your ColorfulThing definition from the last lab.

Part one = parts[0];

Create a new class called ThingContainer; this will be a class designed to hold multiple ColorfulThings.

Give the ThingContainer class an array of ColorfulThings and a constructor that takes one argument: an integer that defines the size of the array.

ThingContainer needs an add method to add ColorfulThings to its array. It should add the ColorfulThings in the order they are received. If the array is full when add is called then it should print the error message "ThingContainer is full"

ThingContainer should also be able to print all of the ColorfulThings it has. Add a printThings method for this.

Create a main method for InitializationLab2. In this method create at least three ThingContainers and test that you can fill them with randomly generated ColorfulThings and that you get the error message described above.

Part 2: Too many things

Let's enhance our ThingContainer. Start by adding a method to remove items. We'll call our method pop, and it should remove the last element in the array of things and return that element.

What if we don't want the last element in the array? Let's add a remove method, and overload it to handle two different cases. Here they are:

1. We call the remove method with a Color value from the enumerated type in ColorfulThing. Remove the first element of that color from the array and return it. Return null if the ThingContainer does not contain a ColorfulThing of that color.
2. We call the remove method with a ColorfulThing object. Remove the ColorfulThing that matches that object and return it; if it is not in the array return null.

Be sure to adjust the elements in the array after each removal so that it stays in order (the next item added should always be added to the end).

Demonstrate the use of all of these new methods in your main method.

Part 3:

Add another constructor to ThingContainer that can take an array of ColorfulThings as its argument. This constructor should initialize its array to match the contents of the array argument.

Modify your main method to test that this new constructor works.