Chapter 8 continuation

7	Open the dome-v2 project. Add a class for video games to the project. Create some video game objects and test that all the methods work as expected.	Done!
8	Order these items into an inheritance hierarchy: apple, ice cream, bread, fruit, food-item, cereal, orange, dessert, chocolate mousse, baguette.	Super class - Food-items and has dessert, apple, cereal, orange, and bread as its sub classes. Dessert is a superclass for subclasses ice-cream and chocolate mousse. Class bread is superclass now and has baguette as its subclass.
9	In what inheritance relationship might a touch pad and a mouse be?	They could be the sub-classes of Computer parts.
10		Every square is rectangle but every rectangle is not square. Therefore, square is a subclass of rectangle.
11	Assume we have four classes: Person, Student, Teacher & PhDStudent. Teacher and Student are both subclasses of Person. PhDStudent is a subclass of Student. Which of the following assignments are legal and why? Person p1 = new Student(); Person p2 = new PhDStudent(); PhDStudent phd1 = new Student(); Teacher t1 = new Person(); Student s1 = new PhDStudent(); s1 = p1; s1 = p2; p1 = s1; t1 = s1; s1= phd1; phd1 = s1;	Person p1 = new Student() because a student is a person. Person p2 = new PhDStudent(); becausea phDStudent is a person. Student s1 = new PhDStudent(); because a PhDStudent is a Student. p1 = s1 because student is a person. s1 = phd1 because a PhD student s a student.
12	Test your answers to the previous question by creating the classes mentioned in that exercise, and trying it out in BlueJ.	Woohoo! its right :)
13	What has to change in the Database class when another item subclass (for example classVideoGame) is added? Why?	Only have to add "extends" to VideoGame class.
14	Use the documentation of the standard class libraries to find out about the inheritance hierarchy of the collection classes. Draw a diagram showing the hierarchy. http://java.sun.com/j2se/1.4.2/docs/api/
15	Go back to the lab-classess project from chapter 1. Add instructors to the project. Use inheritance to avoid code duplication between students and instructors.	Done!
16	Draw an inheritance hierarchy representing parts of a computer system (processor, memory, disk drive, CD drive, printer, scanner, keyboard, mouse, etc.)	Done on paper
17	Look at the code below. You have four classes (O,X,T and M) and a variable of each of these. O o; X x; T t; M m; The following assignments are all legal. m = t; m = x; o = t; The following assignments are all illegal. o = m; o = x; x = o; What can you say about the relationships of these classes?	Done on paper
18	Draw an inheritance hierarchy of AbstractListand all its (direct and indirect) subclasses, as they are defined in the Java standard library. http://java.sun.com/j2se/1.4.2/docs/api/	Done on paper!