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Twenty questions. Mostly multiple choice. A few short answer. Move through the questions with the arrows next to n of 20 in the question box.

Questions of

What does the ln in System.out.println stand for?

Lane

Line

Alone

Natural log

How many lines does the following code print:

System.out.print("Hello");
System.out.println(", world!");
System.out.println("Goodbye!");

1

2

3

4

What’s a good data type type to represent a temperature in degrees Celsius?

int

double

boolean

String

None of the above.

What’s a good data type type to represent the number of teachers at BHS?

int

double

boolean

String

None of the above.

What’s a good data type type to represent the number of dollars in your bank account?

int

double

boolean

String

None of the above.

What’s a good data type type to represent text in almost any characters used by different languages around the world?

int

double

boolean

String

None of the above.

What’s a good data type type to represent whether a senior is allowed to go to the prom?

int

double

boolean

String

None of the above.

What’s a good data type type to represent the number of atoms in the universe?

int

double

boolean

String

None of the above.

Which of these is not an expression?

10

x

int y;

10.5

a + b * c

(int) n

"hello, world!"

Which of these is the correct way to compute the fraction of seniors in a section as a double given the int variables numberOfSeniors and totalNumberOfStudents?

(double) numberOfSeniors / totalNumberOfStudents

(double) (numberOfSeniors / totalNumberOfStudents)

Which of these is would also work to compute the fraction of seniors in a section as a double given the int variables numberOfSeniors and totalNumberOfStudents?

1.0 * numberOfSeniors / totalNumberOfStudents

numberOfSeniors / totalNumberOfStudents * 1.0

Which of these is the correct way to convert the double variable fractionSeniors to a percentage in the range 0 to 100 rounded to the nearest integer.

(int) (fractionSeniors * 100)

(int) fractionSeniors * 100

(int) fractionSeniors * 100 + 0.5

(int) (fractionSeniors * 100 + 0.5)

(int) (fractionSeniors + 0.5 * 100)

(int) (fractionSeniors + 0.5) * 100

Which if these is the correct expression to get the value of the digit in the one’s place?

n / 10

n % 10

n * 10

n / 10.0

What is the value of this expression:

6 - 12 / 3.0

Hit enter to save answer.

What is the value of this expression:

3 / 12 * 8.0

Hit enter to save answer.

What is the value of this expression:

7 - 2 % 3

Hit enter to save answer.

To compute the true mathematical mod of a and b (what a % b would be if % was true mod rather than remainder) you can compute the remainder of a divided by b, add b to that, and then and take the remainder of that whole thing when divided by b. Write an expression that implements that formula in Java using a and b as the two operands.

Hit enter to save answer.

What is x after the following code runs:

int x = 0;
x += 1;
x -= 10;
x *= -3;
x %= 5;
x = x * 2;
x--;

Hit enter to save answer.

Same code as before except we don’t know the initial value of x. This time write out a single expression that expresses the final result in terms of x.

x += 1;
x -= 10;
x *= -3;
x %= 5;
x = x * 2;
x--;

Hit enter to save answer.

Which kind of monster are double values like?

Giant spiders

Orcs

Zombies

Poltergeists