Chapter 4

What will be the value of x after the following code is executed? int x, y = 4, z = 6; x = (y++) * (++z);

28

In the following code, what values could be read into number to terminate the while loop? Scanner keyboard = new Scanner(System.in); System.out.print("Enter a number: "); int number = keyboard.nextInt(); while (number < 100 && number > 500) { System.out.print("Enter another number: "); number = keyboard.nextInt();

Impossible - the boolean condition can never be true//

The do-while loop is ideal in situations where you always want the loop to iterate at least once

True

The while loop has two important parts: (1) a boolean expression that is tested for a true or false value, and (2) a statement or block of statements that is repeated as long as the expression is true.

True

Which of the following are pre-test loops?

While, for

What will be the value of x after the following code is executed? int x = 10, y = 20; while (y < 100) { x += y; y += 20; }

b

Assume that inputFile references a Scanner object that was used to open a file. Which of the following while loops is the correct way to read data from the file until the end of the file is reached?

d. while (inputFile.hasNext()) { ... }

Each repetition of a loop is known as a(n) _______

iteration

Which is a control structure that causes a statement or group of statements to repeat?

loop

A __________ loop will always be executed at least once

posttestloop

A __________ is a value that signals when the end of a list of values has been reached.

sentinel

What will be the values of x aand y after the following code is executed? int x = 12, y = 5; x += y--;

x = 17, y = 4

Which of the following statements will create an object from the Random class?

Random myNumber = new Random();

A loop that repeats a specific number of times is known as a(n) __________ loop

Count-controlled

The while loop is always the best choice in situations where the exact number of iterations is known

False

The while loop is always the best choice in situations where the exact number of iterations is known.

False

When the break statement is encountered in a loop, all the statements in the body of the loop that appear after it are ignored, and the loop prepares for the next iteration.

False

Scanner keyboard = new Scanner(System.in); System.out.print("Enter a number: "); int number = keyboard.nextInt(); while (number < 100 || number > 500) { System.out.print("Enter another number: "); number = keyboard.nextInt();

Numbers 100- 500

Scanner keyboard = new Scanner(System.in); System.out.print("Enter a number: "); int number = keyboard.nextInt(); while (number < 100 || number > 500) { System.out.print("Enter another number: "); number = keyboard.nextInt();

Numbers in the range 100 - 500

Java provides a set of simple unary operators designed just for incrementing and decrementing variables.

T

In a for loop, the control variable cannot be initialized to a constant value and tested against a constant value.

True

What will be the value of x after the following code is executed? int x = 10, y = 20; while (y < 100) { x += y; }

infinite loop

The variable that controls the number of times a loop iterates is known as a(n) _____

loop control variable

Which of the following expressions will generate a random number in the range of 1 through 10?

myNumber = randomNumbers.nextInt(10) + 1;

A random number, created as an object of the Random class, is always a(n) __________.

object

How many times will the following do-while loop be executed? int x = 11; do { x += 20; } while (x > 100);

once because //X is never over 100

Which of the following is the method you can use to determine wether a file exist?

the File class exists method

What will be the values of x and y as a result of the following code? int x = 25, y = 8; x += y++;

x= 33, y = 9

How many times will the following for loop be executed? for (int count = 10; count <= 21; count++) System.out.println("Java is great!");

12// because 10 is printed and 21

What will be the value of x after the following code is executed? int x, y = 15; x = y--;

15. // y-- or y++ does nothing unless in the for loop or before th y

What will be the values of x and y after the following code is executed? int x, y = 15, z = 3; x = (y--) / (++z);

3

int x = 10; for (int y = 5; y < 20; y +=5) x += y; What's the value of X

40

How many times will the following do-while loop be executed? int x = 11; do { x += 20; } while (x <= 100);

5

int x = 11; do { x += 20; } while (x <= 100);

5

What will be printed after the following code is executed? for (int number = 5; number <= 15; number +=3) System.out.print(number + ", ");

5, 8, 11, 14

Select all that apply. Which method of the Random class will return a random number within the range of 0.0 and 1.0? a. nextDouble() c. nextFloat() b. nextLong() d. nextInt(int n)

A, C

Select all that apply. Which of the following steps is normally performed by a for loop? a. update the control variable during each iteration b. test the control variable by comparing it to a maximum or minimum value c. terminate when the control variable reaches its maximum or minimum value d. initialize the control variable to a starting value

ALL