Theme Park - Homework Revising Abstract Classes, Interfaces and Polymorphism.

Learning Objectives

Practice modelling a large real world domain and what you have learned about using:

• classes
• inheritance
• abstract classes
• interfaces

ThemePark

MVP - Classes and Abstract Classes

Model a ThemePark (with various Attraction and Stalls) and its Visitors.

Remember to model class diagrams first, then write tests, then write code.

1. Visitor has age, height, money
2. Using a Attraction abstract class (which has a name), create some subclasses for Rollercoaster, Dodgems, Park, Playground
3. Using a Stall abstract class (which has a name, ownerName and parkingSpot), create some classes for IceCreamStall, CandyFlossStall, TobaccoStall

Extension - Classes and Abstract Classes

4. ThemePark stores all Attractions and Stalls in it.
5. ThemePark has a method visit(Visitor, Attraction)

MVP - Interfaces

Introduce some Interfaces to enable charging, restricting and reviewing attractions and stalls:

1. ITicketed promises double defaultPrice() and double priceFor(Visitor)

2. ISecurity promises boolean isAllowedTo(Visitor)

3. IReviewed promises int getRating() and String getName()

   Have some of the classes implement these interfaces. Below are the rules about what the implementations should be:

4. Playground implements ISecurity because it has a maximum age of 15

5. TobaccoStall implements ISecurity because it has a minimum age of 18

6. Rollercoster implements ISecurity and requires a visitor to be over 145cm tall and over 12 years of age

Extension - Interfaces

Note: Starting prices are: £8.40 Rollercoaster, £4.50 Dodgems, £2.80 IceCreamStall, £4.20 CandyFlossStall, £6.60 TobaccoStall

7. Rollercoaster implement ITicketed and charges tall people over 200cm double fee
8. Dodgems implement ITicketed and charge half price to children under 12 years old
9. All Stalls implement ITicketed but they use a starting price whoever is buying
10. Park and Playground have no ticketing gate so do not implement ITicketed for these, but all other Attractions do.

MVP - Polymorphism

1. All Attractions and Stalls have a class variable int rating
2. All Attractions and Stalls implement IReviewed and implement a getter for int getRating() and String getName()
3. ThemePark has a method getAllReviewed() which returns an ArrayList of IReviewed

Extension - Polymorphism

4. ThemePark has a method getAllAllowedFor(Visitor) which takes a Visitor and returns an ArrayList of ITicketed
5. ThemePark has a method that can return a string with all reviews, returning a String a little bit like this: Rollercoster: 4, Dodgems: 8, Park: 2, IceCream: 6, TobaccoStall: 1