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CAB201 Notes

Worksheet 8 - Inheritance

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Tuesday Class (9-11am) Wednesday Class (9-11am)

Worksheet 8: Inheritance

This week we are looking at inheritance. We will begin by looking at inheritance, before talking about protected visibility, override and the object methods.

Inheritance

  1. Download the Letter.zip from Canvas. It contains a MyDate and a Letter class which contains the name of the recipient and the date mailed.

    Create a CertifiedLetter as a subclass to Letter that also contains a tracking number for each letter.

    Create a TestLetter class that creates multiple Letter and CertifiedLetter objects and prints their values out to the screen.

  2. Create a class named Class. It should contain a field called Name. Write a TestClass that should test the Class.

    Create a class called SubClass, which is a subclass of Class. It should contain a field called Age. In your TestClass write code to test Subclass.

    Create a class called SubSubClass, which is a subclass of SubClass. It should contain a field called Location. In your TestClass write code to test SubSubclass.

Protected Visibility

  1. Download the Person.zip from Canvas. It contains a Person class which should contain a property called name, along with get and set properties for name.

    Create a class called Worker, which inherits the Person class. Worker should contain a protected salary and a private lunch Apply appropriate get and set properties for salary and lunch.

    Create a second class called CEOWoker, which inherits from Worker.

    Create a class called TestWorker. Create a version of CEOWorker in TestWorker, and print all of its details. What are you able to access?

    Create GetSalary and GetLunch in Worker. File them with appropriate code.

    Go back to TestWorker and print out all of the details of your CEO Worker.

    Go back into Worker and add a SetSalary and SetLuch and fill them with appropriate code (feel free to make them up!). Go back to TestWorker and print out all of the details of your CEO Worker.

    Copy and paste the GetSalary, GetLunch, SetSalary and SetLunch from Worker to CEOWorker. Which ones will it not allow you to do?

  2. Create a BiscuitOrder class. The class should accept the following parameters: order number, customer name, cookie type (for example: Chocolate Chip) and number of dozens ordered. Also include a price. Make sure that each of them has a protected access. Create a method that sets the price at $15 per dozen for the first 2 orders and $13 per dozen for the rest. Write a DisplayOrder which prints out all of the order’s details.

    Write a TestBiscuitOrder class that tests the BiscuitOrder classes.

    Write a SpecialCookOrder class which includes a field that describes why it’s a special order (for example gluten free). Override the price method and add $15 if the price is less than $50 and $25 if the price is greater than $50.

    Modify the TestBiscuitOrder to test the SpecialCookOrder class.

Override

  1. Download Photo.zip from Canvas. It contains a Photo class for use in a company that develop photos. It has a constructor that accepts the length and width of photo.

    Create a subclass of Photo called MattedPhoto that holds a string field to represent a colour (for example: black). Add a DisplayPhoto method to print out all the fields.

    Create a subclass called FramedPhoto that holds a field for the frame’s material (such as silver) and style (such as modern). Add a DisplayPhoto method to print out all the fields.

    Create a TestPhoto class to test the MattedPhoto and the FramedPhoto.

  2. Download HospitalPerson.zip from Canvas. It contains a class that holds information about a Person, such as their name. It should also contain a Details method that outputs their name.

    Create a Doctor class which inherits HospitalPerson. It should contain their speciality. It should also contain a Details method which will output their name and their speciality.

    Create a Patient class which inherits HospitalPerson. It should contain their height and weight. The Details method should output their name, height and weight.

    Create a DayPatient which will contain the reason that they are in hospital. The Details method should output their name, height, weight and the reason.

    Create a TestHospitalPerson which will test the Doctor, Patient and DayPatent.

Object Methods

  1. Download the RealEstate.zip from Canvas. It contains a RealEstate class that contains the street number, street, and post code.

    Write a class called House. The constructor should take two additional parameters, whether the house has a pool or a tennis court. Write a ToString() method that will print out all of the fields.

    Write a class called Unit, which should inherit from RealEastate. The constructor should add a unit number. Write a ToString() method that will print out all of the fields.

    Write a class called TestRealEstate. It should import both House and Unit. Write enough information to test all of the classes.

  2. Create an application called JobDemo. It should include Job objects. Each Job should have properties that include a job number, customer name, estimate hours and price for the job. Create a constructor that contains all of the parameters except for price, which is calculated at $45 per hour.

    Create the following methods :

    • A GetHashCode() method that returns the base hash code;
    • An Equals() method that determines if two Jobs are equal if they have the same job number;
    • A ToString() method that returns a strong containing all of their job information.

    Write a class called RushJob. It has a premium of $150 which will add to the cost of a job.

    Write a class called TestJob. It will import both Job and RushJob. Write enough information to test all of the classes.

Homework

  1. You are to create a set of classes called TyreDemo. Create a class called Tyre that contains a field called name. Have name set to the value “Tyre”. Add permissions to access it publicly, but only have it set via its children. Make two subclass for Tyre, one called ScooterTyre which will set the name to “Scooter” and CarTyre which will set the name to “Car”. Write a class called TestTyre, which will test the three classes.

  2. Create and application called MyOrder, which contains an order that sells item for $19.95. You should create an Order class that contains the fields for order number, customer name, quantity order. It should also contain a number for the order price. You should also create the following:

    • An Equals method that determines if two Orders are equal if they have the same order price
    • A GetHashCode method that returns the order number
    • A ToString method that returns a string containing all order information

    You should also write a ShippedOrder class. This class will be a sub class of Order and have a $4.00 shipping fee. Override any methods, parameters or properties of the parent class as necessity.

    Write a TestOrder class. It should test all of the methods. In particular, create classes to test the Equals method.

  3. Image that you have the following User Stores:

    1. As a game player I would like to play a game for my enjoyment
    2. As a game player I would like to know how many people can play a game so I can invite my friends over to play
    3. As a game player I would like to have a separate game that has a time limit so that I know how long to play the game for
    4. As a game player I would like to see the name of the game, how many people can play it and if possible, how long the game would be played for so that I know the details of the game.

    You are to implement the following for Game and GameWithTimeLimit. Design the appropriate classes and then write the code.