Name: ___________________________________________________
Umail Address: ______________________________@ umail.ucsb.edu
Circle one: 5pm 6pm
Please write your name only on this page.
That allows me to grade your exams without knowing whose exam I am grading.
This exam is closed book, closed notes, closed mouth, cell phone off,
except for:
There are 100 points worth of questions on the exam, and you have 75 minutes to complete the exam.
A hint for allocating your time—on your first pass through the exam:
If you do that, after you complete your first pass through the exam in 50 minutes, you'll still have 25 minutes to:
System.out.println("c = " + c); when c is of type Coin. "25 cents", a nickel should return "5 cents", and a penny should return "1 cent". "2 cents", "20 cents" or "42 cents". A dollar coin should return "100 cents". Only the value "1 cent" should be treated as a special case (no s.)There is more room on the next page for your answer if you run out of room here.
Extra space for your answer to question 1
(30 pts) Assume that we have a class Book with attributes title and year (representing copyright year). We have a two-argument constructor that takes title and year, and default constructor that gives title the value "" (empty string) and year the value 0.
Assume that we have overridden the equals() method as follows:
public boolean equals(Object o)
{
if (! o instanceof Book) { return false;}
Book b = (Book) o;
return (b.title.equals(this.title)) && (b.year == this.year);
}
Assume then that we have the following code inside a main method. The spot marked _____ is a blank where we will fill in an expression.
Book t = new Book();
Book u = new Book();
Book v = u;
Book w = new Book("Moby Dick",1851);
Book x = new Book("Moby Dick",1851);
Book y = w;
System.out.println("result =" + ________ ); // we will fill in the blank!
As we demonstrated in class, if we fill in the blank with a boolean expression, when that expression is concatenated with a String, Java will automatically convert it to either the String literal "true" or "false".
A table of boolean expressions appears below, each one involving the Book objects t,u,v,w,x, and y we've constructed above. For each one, indicate if the boolean expression would evaluate to true or false (i.e. whether true or false would be printed after result =)
t == u |
Circle one: true false |
t.equals(u) |
Circle one: true false |
t.equals(v) |
Circle one: true false |
u.equals(v) |
Circle one: true false |
w.equals(w) |
Circle one: true false |
y == w |
Circle one: true false |
w.equals(y) |
Circle one: true false |
w.equals(x) |
Circle one: true false |
y == x |
Circle one: true false |
y.equals(u) |
Circle one: true false |
x and y, each of which has a primitive type.
a and b, each of which ends up being a reference.
Questions 7-10 are on the back page—dont forget them!
boolean?
Total points: ?