Deck 5: Control Structures II: Repetition

Question 1

In the case of the sentinel-controlled while loop, the first item is read before the while loop is entered.

Answer 1

True

Question 2

A loop is a control structure that causes certain statements to be executed over and over until certain conditions are met.

Answer 2

True

Question 3

The following for loop executes 21 times. (Assume all variables are properly declared.) for (i = 1; i <= 20; i = i + 1) System.out.println(i);

Answer 3

False

Question 4

The output of the Java code, assuming that all variables are properly declared, is 32. num = 10; while (num <= 32) num = num + 5; System.out.println(num);

Question 5

In the case of an infinite while loop, the while expression (that is, the loop condition) is always true.

Question 6

To read data from a file of unspecified length, an EOF-controlled while loop is a better choice than a counter-controlled while loop.

Question 7

The control statements in the for loop include the initial expression, logical expression, and update expression.

Question 8

Assume that all variables in the following code are properly declared and that the input is 3 7 4 -1. The output is 13. num = console.nextInt(); sum = num; while (num != -1) {num = console.nextInt(); sum = sum + num;} System.out.println(sum);

Question 9

In the for statement, if the logical expression is omitted, it is assumed to be false.

Question 10

A syntax error will result if the control statements of a for loop are omitted.

Question 11

A loop that continues to execute endlessly is called an endless loop.

Question 12

The loop condition of a while loop is reevaluated before every iteration of the loop.

Question 13

If the while expression becomes false in the middle of the while loop body, the loop terminates immediately.

Question 14

EOF-controlled while loop is another name for sentinel-controlled while loop.

Question 15

A counter-controlled loop is used when the exact number of data entries is known.

Question 16

Control variables are automatically initialized in a loop.

Question 17

A while loop is a post-test loop.

Question 18

The output of the following Java code is: Stoor. int count = 5; System.out.print("Sto"); do {System.out.print('o'); count--;} while (count >= 5); System.out.println('r');

Question 19

Like a do...while loop, the body of a while loop executes at least once.

Question 20

The output of the Java code, assuming that all variables are properly declared, is: 2 3 4 5 6. n = 2; while (n >= 6) {System.out.print(n + " "); n++;} System.out.println();

Question 21

The above code is an example of a(n) ____ loop.

A) flag-controlled
C) EOF-controlled
B) counter-controlled
D) sentinel-controlled

Question 22

The above code is an example of a(n) ____ while loop.

A) flag-controlled
C) EOF-controlled
B) counter-controlled
D) sentinel-controlled

Question 23

Which of the following is the logical expression in the for loop above?

A) i = 0;
B) i <= 10;
C) i++
D) System.out.println("*");

Question 24

Which of the following is NOT a reserved word in Java?

A) do
C) for
B) while
D) loop

Question 25

What is value of x after the following code executes? int x = 0; int i; for (i = 0; i < 5; i++) x = 3 * x + i;

A) 18
C) 179
B) 58
D) 226

Question 26

After a break statement executes, the program continues to execute with the first statement after the structure.

Question 27

Because a do...while loop is a post-test loop, the body of the loop may not execute at all.

Question 28

Which of the following is true about a while loop?

A) The body of the loop is executed at least once.
B) The logical expression controlling the loop is evaluated before the loop is entered and after the loop exists.
C) The body of the loop may not execute at all.
D) It is a post-test loop

Question 29

What is the output of the following Java code? int num = 15; while (num > 0) num = num - 3; System.out.println(num);

A) 0
C) 12
B) 3
D) 15

Question 30

Suppose sum and num are int variables, and the input is 20 25 10 18 -1 What is the output of the following code? (Assume that console is a Scanner object initialized to the standard input device.) sum = 0; num = console.nextInt(); while (num != -1) {if (num >= 20) sum = sum + num; else sum = sum - num; num = console.nextInt();} System.out.println(sum);

A) 17
C) 45
B) 28
D) 60

Question 31

Which of the following is the update expression in the for loop above?

A) i = 0;
B) i <= 10;
C) i++;
D) System.out.println("*");

Question 32

What is the value of counter after the following statements execute? counter = 1; while (counter < 30) counter = 2 * counter;

A) 16
C) 64
B) 32
D) 53

Question 33

If a continue statement is placed in a do...while structure, the loop-continue test is evaluated immediately after the continue statement.

Question 34

The do...while loop has an exit condition but no entry condition.

Question 35

What is the tenth Fibonacci number in the sequence above?

A) 21
C) 55
B) 34
D) 89

Question 36

The above code is an example of a(n) ____ loop.

A) sentinel-controlled
C) EOF-controlled
B) flag-controlled
D) counter-controlled

Question 37

The above code is an example of a(n) ____ while loop.

A) flag-controlled
C) EOF-controlled
B) counter-controlled
D) sentinel-controlled

Question 38

A break statement is legal in a while loop, but not in a for loop.

Question 39

Which of the following is the initial expression in the for loop above?

A) i = 0;
B) i <= 10;
C) i++
D) System.out.println("*");

Question 40

What is the output of the following code? int count; int num = 2; for (count = 1; count < 2; count++) {num = num + 3; System.out.print(num + " ");} System.out.println();

A) 5
C) 2 5 8
B) 5 8
D) 5 8 11

Question 41

Which executes first in a do...while loop?

A) statement
C) initial statement
B) logical expression
D) update expression

Question 42

Which of the following loops is guaranteed to execute at least once?

A) counter-controlled while loop
C) do...while loop
B) for loop
D) sentinel-controlled while loop

Question 43

Where is the continue statement NOT usually used?

A) while loops
C) switch structures
B) for loops
D) do...while loops

Question 44

Which of the following is true about a do...while loop?

A) The body of the loop is executed at least once.
B) The logical expression controlling the loop is evaluated before the loop is entered.
C) The body of the loop may not execute at all.
D) It is a pretest loop.

Question 45

Which executes immediately after a continue statement in a for loop?

A) initial statement
C) loop condition
B) update statement
D) the body of the loop

Question 46

If y = 0, how many times would the loop above execute?

A) 1
C) 3
B) 2
D) 4

Question 47

Which of the following does not have an entry condition?

A) EOF-controlled while loop
C) do...while loop
B) sentinel-controlled while loop
D) for loop

Question 48

What is the final value of x in the code above?

A) 0
C) 9
B) 3
D) 27

Question 49

How many times does the statement above execute?

A) none
C) twice
B) once
D) three times

Question 50

Which of the following is not a function of the break statement?

A) To exit early from a loop
B) To skip the remainder of a switch structure
C) To eliminate the use of certain boolean variables in a loop
D) To ignore certain values for variables and continue with the next iteration of a loop