Chapter 11

Question 1

1. What is a primitive data type?

Answer 1

1. A data type that is built into the C++ language, such as int, char, float, etc.

Question 2

2. Does a structure declaration cause a structure variable to be created?

Answer 2

No

Question 3

3. Both arrays and structures are capable of storing multiple values. What is the difference between an array and a structure?

Answer 3

3. The elements of an array must all be of the same data type. The members of a structure may be of different data types.

Question 4

4. Look at the following structure declaration.
   struct Point
   {
   int x;
   int y;
   };
   Write statements that
   A) define a Point structure variable named center
   B) assign 12 to the x member of center
   C) assign 7 to the y member of center
   D) display the contents of the x and y members of center

Answer 4

A) Point center;
B) center.x = 12;
C) center.y = 7;
D) cout «_space;center.x «_space;endl;
cout «_space;center.y «_space;endl;

Question 5

5. Look at the following structure declaration.
   struct FullName
   {
   string lastName;
   string middleName;
   string firstName;
   };
   Write statements that
   A) Define a FullName structure variable named info
   B) Assign your last, middle, and first name to the members of the info variable
   C) Display the contents of the members of the info variable

Answer 5

A) FullName info;
B) info.lastName = “Smith”;
info.middleName = “Bart”;
info.firstName = “William”;
C) cout «_space;info.lastName «_space;endl;
cout «_space;info.middleName «_space;endl;
cout «_space;info.firstName «_space;endl;

Question 6

6. Look at the following code.
   struct PartData
   {
   string partName;
   int idNumber;
   };
   PartData inventory[100];
   Write a statement that displays the contents of the partName member of element 49 of the inventory array.

Answer 6

6. cout «_space;inventory[49].partName «_space;endl;

Question 7

7. Look at the following code.
   struct Town
   {
   string townName;
   string countyName;
   double population;
   double elevation;
   };
   Town t = { “Canton”, “Haywood”, 9478 };
   A) What value is stored in t.townName ?
   B) What value is stored in t.countyName ?
   C) What value is stored in t.population ?
   D) What value is stored in t.elevation ?

Answer 7

A) “Canton”
B) “Haywood”
C) 9478
D) uninitialized

Question 8

structure Rectangle
{
int length;
int width;
};
Rectangle *r = nullptr
Write statements that
A) Dynamically allocate a Rectangle structure variable and use r to point to it.
B) Assign 10 to the structure’s length member and 14 to the structure’s width member.

Answer 8

A) r = new Rectangle;
B) r->length = 10;
r->width = 14;

Question 9

9. What is the difference between a union and a structure?

Answer 9

9. All the members of a union occupy the same area of memory, whereas the members of a structure have their own memory locations.

Question 10

10. Look at the following code.
    union Values
    {
    int ivalue;
    double dvalue;
    };
    Values v;
    Assuming that an int uses four bytes and a double uses eight bytes, how much memory does the variable v use?

Answer 10

8 bytes

Question 11

11. What will the following code display?
    enum { POODLE, BOXER, TERRIER };
    cout «_space;POODLE «_space;” “ «_space;BOXER «_space;” “ «_space;TERRIER «_space;endl;

Answer 11

0 1 2

Question 12

12. Look at the following declaration.
    enum Person { BILL, JOHN, CLAIRE, BOB };
    Person p;
    Indicate whether each of the following statements or expressions is valid or invalid.
    A) p = BOB;
    B) p ++ ;
    C) BILL > BOB
    D) p = 0;
    E) int x = BILL;
    F) p = static_cast<Person>(3);
    G) cout << CLAIRE << endl;</Person>

Answer 12

A) valid
B) invalid
C) valid
D) invalid
E) valid
F) valid
G) valid

Question 13

13. Before a structure variable can be created, the structure must be _________.

Answer 13

declared

Question 14

14. The _________ is the name of the structure type.

Answer 14

tag

Question 15

15. The variables declared inside a structure declaration are called _________.

Answer 15

members

Question 16

16. A(n) _________ is required after the closing brace of a structure declaration.

Answer 16

semicolon

Question 17

17. In the definition of a structure variable, the _________ is placed before the variable name, just like the data type of a regular variable is placed before its name.

Answer 17

tag

Question 18

18. The _________ operator allows you to access structure members.

Answer 18

dot

Question 19

19. The structure Car is declared as follows:
    struct Car
    {
    string carMake;
    string carModel;
    int yearModel;
    double cost;
    };
    Write a definition statement that defines a Car structure variable initialized with the following data:
    Make: Ford
    Model: Mustang
    Year Model: 1968
    Cost: $20,000

Answer 19

19. Car hotRod = {“Ford”, “Mustang”, 1968, 20000};

Question 20

20. Define an array of 25 of the Car structure variables

struct Car
{
string carMake;
string carModel;
int yearModel;
double cost;
};
Write a definition statement that defines a Car structure variable initialized with the following data:
Make: Ford
Model: Mustang
Year Model: 1968
Cost: $20,000

Answer 20

const int SIZE = 25;
Car collection[SIZE];

Question 21

21. Define an array of 35 of the Car structure variables. Initialize the first three elements with the following data:
    Make Model Year Cost
    Ford Taurus 1997 $ 21,000
    Honda Accord 1992 $ 11,000
    Lamborghini Countach 1997 $200,000

Answer 21

const int SIZE = 35;
Car forSale[SIZE] = {
{“Ford”, “Taurus”, 1997, 21000},
{“Honda”, “Accord”, 1992, 11000},
{“Lamborghini”, “Countach”, 1997, 200000} };

Question 22

22. Write a loop that will step through the array you defined in Question 21, displaying the contents of each element.

Answer 22

for (int x = 0; x < SIZE; x++)
{
cout «_space;forSale[x].carMake «_space;endl;
cout «_space;forSale[x].carModel «_space;endl;
cout «_space;forSale[x].yearModel «_space;endl;
cout «_space;forSale[x].cost «_space;endl «_space;endl;
}

Question 23

23. Declare a structure named TempScale, with the following members:
    fahrenheit: a double
    centigrade: a double
    Next, declare a structure named Reading, with the following members:
    windSpeed: an int
    humidity: a double
    temperature: a TempScale structure variable
    Next define a Reading structure variable.

Answer 23

struct TempScale
{
double fahrenheit;
double centigrade;
};
struct Reading
{
int windSpeed;
double humidity;
tempScale temperature;
};
Reading today;

Question 24

24. Write statements that will store the following data in the variable you defined in
    Question 23.
    Wind Speed: 37 mph
    Humidity: 32%
    Fahrenheit temperature: 32 degrees
    Centigrade temperature: 0 degrees

Answer 24

today.windSpeed = 37;
today.humidity = .32;
today.temperature.fahrenheit = 32;
today.temperature.centigrade = 0;

Question 25

25. Write a function called showReading . It should accept a Reading structure variable (see Question 23) as its argument. The function should display the contents of the variable on the screen.

Answer 25

void showReading(Reading values) { cout << "Wind speed: " << values.windSpeed << endl; cout << "Humidity: " << values.humidity << endl; cout << "Fahrenheit temperature: " << values.temperature.fahrenheit << endl; cout << "Centigrade temperature: " << values.temperature.centigrade << endl; }

Question 26

26. Write a function called findReading . It should use a Reading structure reference variable (see Question 23) as its parameter. The function should ask the user to enter values for each member of the structure.

Answer 26

void findReading(Reading &r) { cout << "Enter the wind speed: "; cin >> r.windSpeed; cout << "Enter the humidity: "; cin >> r.humidity; cout << "Enter the fahrenheit temperature: "; cin >> r.temperature.fahrenheit; cout << "Enter the centigrade temperature: "; cin >> r.temperature.centigrade; }

Question 27

27. Write a function called getReading , which returns a Reading structure (see Question

Answer 27

Reading getReading() { Reading local; cout << "Enter the following values:\n"; cout << "Wind speed: "; cin >> local.windSpeed; cout << "Humidity: "; cin >> local.humidity; cout << "Fahrenheit temperature: "; cin >> local.temperature.fahrenheit; cout << "Centigrade temperature: "; cin >> local.temperature.centigrade; return local; }

Question 28

28. Write a function called recordReading . It should use a Reading structure pointer variable (see Question 23) as its parameter. The function should ask the user to enter values for each member of the structure pointed to by the parameter.

Answer 28

void recordReading(Reading *r) { cout << "Enter the wind speed: "; cin >> r->windSpeed; cout << "Enter the humidity: "; cin >> r->humidity; cout << "Enter the fahrenheit temperature: "; cin >> r->temperature.fahrenheit; cout << "Enter the centigrade temperature: "; cin >> r->temperature.centigrade; }

Question 29

29. Rewrite the following statement using the structure pointer operator: (*rptr).windSpeed = 50;

Answer 29

29. rptr->WindSpeed = 50;

Question 30

30. Rewrite the following statement using the structure pointer operator: *(*strPtr).num = 10;

Answer 30

30. strPtr->num = 10;

Question 31

31. Write the declaration of a union called Items with the following members: alpha a character num an integer bigNum a long integer real a float Next, write the definition of an Items union variable.

Answer 31

union Items { char alpha; int num; long bigNum; float real; }; Items x;

Question 32

32. Write the declaration of an anonymous union with the same members as the union you declared in Question 31.

Answer 32

union { char alpha; int num; long bigNum; float real; };

Question 33

33. Write a statement that stores the number 452 in the num member of the anonymous union you declared in Question 32.

Answer 33

33. num = 452;

Question 34

34. Look at the following statement. enum Color { RED, ORANGE, GREEN, BLUE }; A) What is the name of the data type declared by this statement? B) What are the enumerators for this type? C) Write a statement that defines a variable of this type and initializes it with a valid value.

Answer 34

A) Color B) RED, ORANGE, GREEN, and BLUE C) Color myColor = BLUE;

Question 35

35. A pet store sells dogs, cats, birds, and hamsters. Write a declaration for an anonymous enumerated data type that can represent the types of pets the store sells

Answer 35

35. enum Pets { DOGS, CATS, BIRDS, HAMSTERS };

Question 36

36. T F A semicolon is required after the closing brace of a structure or union declaration.

Answer 36

true

Question 37

37. T F A structure declaration does not define a variable.

Answer 37

true

Question 38

38. T F The contents of a structure variable can be displayed by passing the structure variable to the cout object.

Answer 38

false

Question 39

39. T F Structure variables may not be initialized.

Answer 39

false

Question 40

40. T F In a structure variable’s initialization list, you do not have to provide initializers for all the members.

Answer 40

true

Question 41

41. T F You may skip members in a structure’s initialization list.

Answer 41

false

Question 42

42. T F The following expression refers to element 5 in the array carInfo : carInfo.model[5]

Answer 42

false

Question 43

43. T F An array of structures may be initialized.

Answer 43

true

Question 44

44. T F A structure variable may not be a member of another structure.

Answer 44

false

Question 45

45. T F A structure member variable may be passed to a function as an argument.

Answer 45

true

Question 46

46. T F An entire structure may not be passed to a function as an argument.

Answer 46

false

Question 47

47. T F A function may return a structure.

Answer 47

true

Question 48

48. T F When a function returns a structure, it is always necessary for the function to have a local structure variable to hold the member values that are to be returned.

Answer 48

true

Question 49

49. T F The indirection operator has higher precedence than the dot operator.

Answer 49

false

Question 50

50. T F The structure pointer operator does not automatically dereference the structure pointer on its left.

Answer 50

false

Question 51

51. T F In a union , all the members are stored in different memory locations.

Answer 51

false

Question 52

52. T F All the members of a union may be used simultaneously.

Answer 52

false

Question 53

53. T F You may define arrays of union s.

Answer 53

true

Question 54

54. T F You may not define pointers to union s.

Answer 54

false

Question 55

55. T F An anonymous union has no name.

Answer 55

true

Question 56

56. T F If an anonymous union is defined globally (outside all functions), it must be declared static .

Answer 56

true

Question 57

57. struct { int x; float y; }; Find the Errors

Answer 57

57. The structure declaration has no tag.

Question 58

58. struct Values { string name; int age; } Find the Errors

Answer 58

58. The semicolon is missing after the closing brace.

Question 59

59. struct TwoVals { int a, b; }; int main () { TwoVals.a = 10; TwoVals.b = 20; return 0; } Find the Errors

Answer 59

59. No structure variable has been declared. TwoVals is the structure tag.

Question 60

60. #include using namespace std; struct ThreeVals { int a, b, c; }; int main() { ThreeVals vals = {1, 2, 3}; cout << vals << endl; return 0; } Find the Errors

Answer 60

60. In the definition of vals, TwoVals is used as the type instead of ThreeVals. An entire struct cannot be sent to cout.

Question 61

61. #include #include using namespace std; struct names { string first; string last; }; int main () { names customer = "Smith", "Orley"; cout << names.first << endl; cout << names.last << endl; return 0; } Find the Errors

Answer 61

61. The initialization list of the customer variable must be enclosed in braces.

Question 62

62. struct FourVals { int a, b, c, d; }; int main () { FourVals nums = {1, 2, , 4}; return 0; Find the Errors

Answer 62

62. An initializer cannot be skipped before the end of the initialization list.

Question 63

using namespace std; struct TwoVals { int a = 5; int b = 10; }; int main() { TwoVals v; cout << v.a << " " << v.b; return 0; } Find the Errors

Answer 63

63. Structure members cannot be initialized in the structure definition.

Question 64

64. struct TwoVals { int a = 5; int b = 10; }; int main() { TwoVals varray[10]; varray.a[0] = 1; return 0; } Find the Errors

Answer 64

Structure members cannot be initialized in the structure definition. The statement varray.a[0] = 1 should read: varray[0].a = 1;

Question 65

65. struct TwoVals { int a; int b; }; TwoVals getVals() { TwoVals.a = TwoVals.b = 0; } Find the Errors

Answer 65

65. The function must define a variable of the TwoVals structure. The variable, then, should be used in the assignment statement.

Question 66

66. struct ThreeVals { int a, b, c; }; int main () { TwoVals s, *sptr = nullptr; sptr = &s; *sptr.a = 1; return 0; } Find the Errors

Answer 66

66. In the declaration of the structure variables in main, TwoVals is used as the type instead of ThreeVals. The statement that reads *sptr.A = 1; should read sptr->A = 1;

Question 67

67. #include using namespace std; union Compound { int x; float y; }; Find the Errors

Answer 67

67. Both x and y cannot be meaningfully used at the same time.