Classes - Building Java Programs: A Back to Basics Approach - page 546

10. (You must complete Self-Check Problem 7 before answering this question.)
Add two new methods to the Name class:
public String getNormalOrder()
Returns the person's name in normal order, with the first name followed by the middle initial and last name. For exam-
ple, if the first name is "John" , the middle initial is "Q" and the last name is "Public" , returns "John Q. Public" .
public String getReverseOrder()
Returns the person's name in reverse order, with the last name preceding the first name and middle initial. For example,
if the first name is "John" , the middle initial is "Q" , and the last name is "Public" , returns "Public, John Q." .
11. How do you write a class whose objects can easily be printed on the console?
12. The Point class in the java.awt package has a toString method that returns a String in the following format:
java.awt.Point[x=7,y=2]
Write a modified version of the toString method on our Point class that returns a result in this format.
13. (You must complete Self-Check Problem 7 before answering this question.)
Write a toString method for the Name class that returns a String such as "John Q. Public" .
Section 8.3: Object Initialization: Constructors
14. What is a constructor? How is a constructor different from other methods?
15. What are two major problems with the following constructor?
public void Point(int initialX, int initialY) {
int x = initialX;
int y = initialY;
}
16. (You must complete Self-Check Problem 7 before answering this question.)
Add a constructor to the Name class that accepts a first name, middle initial, and last name as parameters and
initializes the Name object's state with those values.
17. What is the meaning of the keyword this ? Describe three ways that the keyword can be used.
18. Add a constructor to the Point class that accepts another Point as a parameter and initializes this new Point to
have the same ( x, y ) values. Use the keyword this in your solution.
Section 8.4: Encapsulation
19. What is abstraction? How do objects provide abstraction?
20. What is the difference between the public and private keywords? What items should be declared private ?
21. When fields are made private, client programs cannot see them directly. How do you allow classes access to read these
fields' values, without letting the client break the object's encapsulation?
22. Add methods named setX and setY to the Point class that allow clients to change a Point object's x - and
y -coordinates, respectively.
23. (You must complete Self-Check Problem 7 before answering this question.)
Encapsulate the Name class. Make its fields private and add appropriate accessor methods to the class.