CHAPTER 5 (16-33, 34-70) REVIEW QUESTIONS

Question 1

16. To __________ a value means to increase it by one, and to __________ a value means to decrease it by one.

Answer 1

16. increment, decrement

Question 2

17. When the increment or decrement operator is placed before the operand (or to the operand’s left), the operator is being used in __________ mode.

Answer 2

17. prefix

Question 3

18. When the increment or decrement operator is placed after the operand (or to the operand’s right), the operator is being used in __________ mode.

Answer 3

18. postfix

Question 4

19. The statement or block that is repeated is known as the __________ of the loop.

Answer 4

19. body

Question 5

20. Each repetition of a loop is known as a(n) __________.

Answer 5

20. iteration

Question 6

21. A loop that evaluates its test expression before each repetition is a(n) __________ loop.

Answer 6

21. pretest

Question 7

22. A loop that evaluates its test expression after each repetition is a(n) __________ loop.

Answer 7

22. posttest

Question 8

23. A loop that does not have a way of stopping is a(n) __________ loop.

Answer 8

23. infinite or endless

Question 9

24. A(n) __________ is a variable that “counts” the number of times a loop repeats.

Answer 9

24. counter

Question 10

25. A(n) __________ is a sum of numbers that accumulates with each iteration of a loop.

Answer 10

25. running total

Question 11

26. A(n) __________ is a variable that is initialized to some starting value, usually zero, and then has numbers added to it in each iteration of a loop.

Answer 11

26. accumulator

Question 12

27. A(n) __________ is a special value that marks the end of a series of values.

Answer 12

27. sentinel

Question 13

28. The __________ loop always iterates at least once.

Answer 13

28. do-while

Question 14

29. The __________ and __________ loops will not iterate at all if their test expressions are false to start with.

Answer 14

29. while and for

Question 15

30. The __________ loop is ideal for situations that require a counter.

Answer 15

30. for

Question 16

31. Inside the for loop’s parentheses, the first expression is the __________ , the second expression is the __________ , and the third expression is the __________.

Answer 16

31. initialization, test, update

Question 17

32. A loop that is inside another is called a(n) __________ loop.

Answer 17

32. nested

Question 18

33. The __________ statement causes a loop to terminate immediately.

Answer 18

33. break

Question 19

34. The __________ statement causes a loop to skip the remaining statements in the current iteration.

Answer 19

34. continue

Question 20

47. T F The operand of the increment and decrement operators can be any valid mathematical expression.

Answer 20

47. false

Question 21

48. T F The cout statement in the following program segment will display 5:
    int x = 5;
    cout &laquo_space;x++;

Answer 21

48. true

Question 22

49. T F The cout statement in the following program segment will display 5:
    int x = 5;
    cout &laquo_space;++x;

Answer 22

49. false

Question 23

50. T F The while loop is a pretest loop.

Answer 23

50. true

Question 24

51. T F The do-while loop is a pretest loop.

Answer 24

51. false

Question 25

52. T F The for loop is a posttest loop.

Answer 25

52. false

Question 26

53. T F It is not necessary to initialize counter variables.

Answer 26

53. false

Question 27

54. T F All three of the for loop’s expressions may be omitted.

Answer 27

54. true

Question 28

55. T F One limitation of the for loop is that only one variable may be initialized in the initialization expression.

Answer 28

55. false

Question 29

56. T F Variables may be defined inside the body of a loop.

Answer 29

56. true

Question 30

57. T F A variable may be defined in the initialization expression of the for loop.

Answer 30

57. true

Question 31

58. T F In a nested loop, the outer loop executes faster than the inner loop.

Answer 31

58. false

Question 32

59. T F In a nested loop, the inner loop goes through all of its iterations for every single iteration of the outer loop.

Answer 32

59. true

Question 33

60. T F To calculate the total number of iterations of a nested loop, add the number of iterations of all the loops.

Answer 33

60. false

Question 34

62. T F The continue statement causes a terminated loop to resume.

Answer 34

62. false

Question 34

61. T F The break statement causes a loop to stop the current iteration and begin the next one.

Answer 34

61. false

Question 35

63. T F In a nested loop, the break statement only interrupts the loop it is placed in.

Answer 35

63. true

Question 36

64. T F When you call an ofstream object’s open member function, the specified file will be erased if it already exists.

Answer 36

64. true

Question 37

Find the Errors. Each of the following programs has errors. Find as many as you can. 65. // Find the error in this program. #include using namespace std; int main() { int num1 = 0, num2 = 10, result; num1++; result = ++(num1 + num2); cout << num1 << " " << num2 << " " << result; return 0; }

Answer 37

65. The statement result = ++(num1 + num2); is invalid.

Question 38

Find the Errors. Each of the following programs has errors. Find as many as you can. 66. // This program adds two numbers entered by the user. #include using namespace std; int main() { int num1, num2; char again; while (again == 'y' || again == 'Y') cout << "Enter a number: "; cin >> num1; cout << "Enter another number: "; cin >> num2; cout << "Their sum is << (num1 + num2) << endl; cout << "Do you want to do this again? "; cin >> again; return 0; }

Answer 38

66. The while loop tests the variable again before any values are stored in it. The while loop is missing its opening and closing braces.

Question 39

Find the Errors. Each of the following programs has errors. Find as many as you can. 67. // This program uses a loop to raise a number to a power. #include using namespace std; int main() { int num, bigNum, power, count; cout << "Enter an integer: "; cin >> num; cout << "What power do you want it raised to? "; cin >> power; bigNum = num; while (count++ < power); bigNum *= num; cout << "The result is << bigNum << endl; return 0; }

Answer 39

67. The while statement should not end with a semicolon. It could also be argued that bigNum should be defined a long. count should be initialized to 1.

Question 40

Find the Errors. Each of the following programs has errors. Find as many as you can. 68. // This program averages a set of numbers. #include using namespace std; int main() { int numCount, total; double average; cout << "How many numbers do you want to average? "; cin >> numCount; for (int count = 0; count < numCount; count++) { int num; cout << "Enter a number: "; cin >> num; total += num; count++; } average = total / numCount; cout << "The average is << average << endl; return 0; }

Answer 40

The variable total is not initialized to 0. The statement that calculates the average performs integer division. It should use a type cast to cast either total or numCount to a double. The variable count is incremented in the for loop's update expression and again within the for loop.

Question 41

Find the Errors. Each of the following programs has errors. Find as many as you can. 69. // This program displays the sum of two numbers. #include using namespace std; int main() { int choice, num1, num2; do { cout << "Enter a number: "; cin >> num1; cout << "Enter another number: "; cin >> num2; cout << "Their sum is " << (num1 + num2) << endl; cout << "Do you want to do this again?\n"; cout << "1 = yes, 0 = no\n"; cin >> choice; } while (choice = 1) return 0; }

Answer 41

The expression tested by the do-while loop should be choice == 1 instead of choice = 1.

Question 42

Find the Errors. Each of the following programs has errors. Find as many as you can. 70. // This program displays the sum of the numbers 1-100. #include using namespace std; int main() { int count = 1, total; while (count <= 100) total += count; cout << "The sum of the numbers 1-100 is "; cout << total << endl; return 0; }

Answer 42

The variable total is not initialized to 0. The while loop does not change the value of count, so it iterates an infinite number of times.