ch7

Question 1

7.1 De ne the following arrays:
A) empNums, a 100-element array of ints
B) payRates, a 25-element array of floats
C) miles, a 14-element array of longs
D) cityName, a 26-element array of string objects
E) lightYears, a 1,000-element array of doubles

Answer 1

7.1 A) int empNums[100];
B) float payRates[25];
C) long miles[14];
D) string cityNames[26];
E) double lightYears[1000];

Question 2

7.2 What s wrong with the following array definitions?
int readings[-1];
float measurements[4.5];
int size;
string names[size];

Answer 2

7.2 int readings[-1]; // Size declarator cannot be negative
float measurements[4.5]; // Size declarator must be an integer
int size;
string names[size]; // Size declarator must be a constant

Question 3

7.3 What would the valid subscript values be in a four-element array of doubles?

Answer 3

7.3 0 through 3

Question 4

7.4 What is the difference between an array s size declarator and a subscript?

Answer 4

7.4 The size declarator is used in the array declaration statement. It specifies the number of
elements in the array. A subscript is used to access an individual element in an array.

Question 5

7.5 What is array bounds checking ? Does C++ perform it?

Answer 5

7.5 Array bounds checking is a safeguard provided by some languages. It prevents a program
from using a subscript that is beyond the boundaries of an array. C++ does not perform
array bounds checking.

Question 6

7.6 What is the output of the following code?
int values[5], count;
for (count = 0; count

Answer 6

7.6 
1
2
3
4
5

Question 7

7.7 The following program skeleton contains a 20-element array of ints called fish.
When completed, the program should ask how many sh were caught by shermen
1 through 20, and store this data in the array. Complete the program.
#include 
using namespace std;
int main()
{
const int NUM_FISH = 20;
int fish[NUM_FISH];
// You must finish this program. It should ask how
// many fish were caught by fishermen 1-20, and
// store this data in the array fish.
return 0;
}

Answer 7

7.7 #include 
using namespace std;
int main()
{
const int NUM_FISH = 20;
int fish[NUM_FISH], count;
cout > fish[count];
}
return 0;
}

Question 8

7.8 De ne the following arrays:
A) ages, a 10-element array of ints initialized with the values 5, 7, 9, 14, 15,
17, 18, 19, 21, and 23.
B) temps, a 7-element array of floats initialized with the values 14.7, 16.3,
18.43, 21.09, 17.9, 18.76, and 26.7.
C) alpha, an 8-element array of chars initialized with the values J , B , L, A,
* , $ , H , and M .

Answer 8

7.8 A) int ages[10] = {5, 7, 9, 14, 15, 17, 18, 19, 21, 23};
B) float temps[7] = {14.7, 16.3, 18.43, 21.09, 17.9, 18.76, 26.7};
C) char alpha[8] = {‘J’, ‘B’, ‘L’, ‘A’, ‘*’, ‘$’, ‘H’, ‘M’};

Question 9

7.9 Is each of the following a valid or invalid array definition? (If a definition is
invalid, explain why.)
int numbers[10] = {0, 0, 1, 0, 0, 1, 0, 0, 1, 1};
int matrix[5] = {1, 2, 3, 4, 5, 6, 7};
double radii[10] = {3.2, 4.7};
int table[7] = {2, , , 27, , 45, 39};
char codes[] = {‘A’, ‘X’, ‘1’, ‘2’, ‘s’};
int blanks[];

Answer 9

7.9 The definition of numbers is valid.
The declaration of matrix is invalid because there are too many values in the initialization list.
The definition of radii is valid.
The definition of table is invalid. Values cannot be skipped in the initialization list.
The definition of codes is valid.
The definition of blanks is invalid. An initialization list must be provided when an array
is implicitly sized.

Question 10

7.10 Given the following array definition:
int values[] = {2, 6, 10, 14};
What does each of the following display?
A) cout

Answer 10

7.10 A) 0
B) 3
C) 6
D) 14

Question 11

7.11 Given the following array definition:
int nums[5] = {1, 2, 3};
What will the following statement display?
cout &laquo_space;nums[3];

Answer 11

7.11 0

Question 12

7.12 What is the output of the following code? (You may need to use a calculator.)
double balance[5] = {100.0, 250.0, 325.0, 500.0, 1100.0};
const double INTRATE = 0.1;
cout

Answer 12

7. 12
8. 00
9. 00
10. 50
11. 00
12. 00

Question 13

7.13 What is the output of the following code? (You may need to use a calculator.)
const int SIZE = 5;
int time[SIZE] = {1, 2, 3, 4, 5},
speed[SIZE] = {18, 4, 27, 52, 100},
dist[SIZE];
for (int count = 0; count

Answer 13

7.13 
1 18 18
2 4 8
3 27 81
4 52 208
5 100 500

Question 14

7.14 Given the following array definitions
double array1[4] = {1.2, 3.2, 4.2, 5.2};
double array2[4];
will the following statement work? If not, why?
array2 = array1;

Answer 14

7.14 No. An entire array cannot be copied in a single statement with the = operator. The array
must be copied element-by-element.

Question 15

7.15 When an array name is passed to a function, what is actually being passed?

Answer 15

7.15 The address of the array.

Question 16

7.16 When used as function arguments, are arrays passed by value?

Answer 16

7.16 No.

Question 17

7.17 What is the output of the following program? (You may need to consult the
ASCII table in Appendix B.)
#include 
using namespace std;
// Function prototypes
void fillArray(char [], int);
void showArray(const char [], int);
int main ()
{
const int SIZE = 8;
char prodCode[SIZE] = {'0', '0', '0', '0', '0', '0', '0', '0'};
fillArray(prodCode, SIZE);
showArray(prodCode, SIZE);
return 0;
}
// Definition of function fillArray.
// (Hint: 65 is the ASCII code for 'A')
void fillArray(char arr[], int size)
{
char code = 65;
for (int k = 0; k

Answer 17

7.17 ABCDEFGH

Question 18

7.18 The following program skeleton, when completed, will ask the user to enter 10
integers, which are stored in an array. The function avgArray, which you must
write, is to calculate and return the average of the numbers entered.
#include 
using namespace std;
// Write your function prototype here
int main()
{
const int SIZE = 10;
int userNums[SIZE];
cout > userNums[count];
}
cout

Answer 18

7.18 (The entire program is shown here.)
#include 
using namespace std;
// Function prototype here
double avgArray(int []);
int main()
{
const int SIZE = 10;
int userNums[SIZE];
cout > userNums[count];
}
cout

Question 19

7.19 Define a two-dimensional array of ints named grades. It should have 30 rows
and 10 columns.

Answer 19

7.19 int grades[30][10];

Question 20

7.20 How many elements are in the following array?

double sales[6][4];

Answer 20

7.20 24

Question 21

7.21 Write a statement that assigns the value 56893.12 to the first column of the first
row of the array defined in Question 7.20.

Answer 21

7.21 sales[0][0] = 56893.12;

Question 22

7.22 Write a statement that displays the contents of the last column of the last row of
the array defined in Question 7.20.

Answer 22

7.22 cout &laquo_space;sales[5][3];

Question 23

7.23 Define a two-dimensional array named settings large enough to hold the table
of data below. Initialize the array with the values in the table.
12 24 32 21 42
14 67 87 65 90
19 1 24 12 8

Answer 23

7.23 int settings[3][5] = {{12, 24, 32, 21, 42},
{14, 67, 87, 65, 90},
{19, 1, 24, 12, 8}};

Question 24

7.24 Fill in the table below so it shows the contents of the following array:
int table[3][4] = {{2, 3}, {7, 9, 2}, {1}};

Answer 24

2 3 0 0
7 9 2 0
1 0 0 0

Question 25

7.25 Write a function called displayArray7. The function should accept a twodimensional
array as an argument and display its contents on the screen. The
function should work with any of the following arrays:
int hours[5][7];
int stamps[8][7];
int autos[12][7];
int cats[50][7];

Answer 25

7.25 void displayArray7(int arr[][7], int rows)
{
for (int x = 0; x

Question 26

7.26 A video rental store keeps DVDs on 50 racks with 10 shelves each. Each shelf
holds 25 DVDs. Define a three-dimensional array large enough to represent the
store s storage system.

Answer 26

7.26 int vidNum[50][10][25];

Question 27

7.27 What header file must you #include in order to define vector objects?

Answer 27

7.27 vector

Question 28

7.28 Write a definition statement for a vector named frogs. frogs should be an
empty vector of ints.

Answer 28

7.28 vector frogs;

Question 29

7.29 Write a definition statement for a vector named lizards. lizards should be a
vector of 20 floats.

Answer 29

7.29 vector lizards(20);

Question 30

7.30 Write a definition statement for a vector named toads. toads should be a vector
of 100 chars, with each element initialized to ‘Z’.

Answer 30

7.30 vector toads(100, ‘Z’);

Question 31

7.31 gators is an empty vector of ints. Write a statement that stores the value 27 in
gators.

Answer 31

7. 31 vector gators;

gators. push_back(27);

Question 32

7.32 snakes is a vector of doubles, with 10 elements. Write a statement that stores
the value 12.897 in element 4 of the snakes vector.

Answer 32

7.32 snakes[4] = 12.897;

Question 33

Short Answer

1. What is the difference between a size declarator and a subscript?

Answer 33

1. The size declarator is used in a definition of an array to indicate the number of elements the
   array will have. A subscript is used to access a specific element in an array.

Question 34

2. Look at the following array definition.
   int values[10];
   How many elements does the array have?
   What is the subscript of the first element in the array?
   What is the subscript of the last element in the array?
   Assuming that an int uses four bytes of memory, how much memory does the array use?

Answer 34

10
zero
9
40 bytes of memory

Question 35

3. Why should a function that accepts an array as an argument, and processes that
   array, also accept an argument specifying the array s size?

Answer 35

3. Because, with the array alone the function has no way of determining the number of elements
   it has.

Question 36

4. Consider the following array definition:
   int values[5] = { 4, 7, 6, 8, 2 };
   What does each of the following statements display?
   cout

Answer 36

will display value2;
will display value 14;
will display value 8

Question 37

5. How do you define an array without providing a size declarator?

Answer 37

5. By providing an initialization list. The array is sized to hold the number of values in the list.

Question 38

6. Look at the following array definition.
   int numbers[5] = { 1, 2, 3 };
   What value is stored in numbers[2]?
   What value is stored in numbers[4]?

Answer 38

given an array definition.

int numbers[5] = {1, 2, 3};
the value stored in numbers[2] is 3.
the value stored in number[4] is 0, because it’s value not initialized

Question 39

7. Assuming that array1 and array2 are both arrays, why is it not possible to assign
   the contents of array2 to array1 with the following statement?
   array1 = array2;

Answer 39

7. Because an array name without brackets and a subscript represents the array’s beginning
   memory address. The statement shown attempts to assign the address of array2 to array1,
   which is not permitted.

Question 40

8. Assuming that numbers is an array of doubles, will the following statement display
   the contents of the array?
   cout &laquo_space;numbers &laquo_space;endl;

Answer 40

cout &laquo_space;numbers &laquo_space;endl;

the statement will not display the contents of array instead it display memory address

Question 41

9. Is an array passed to a function by value or by reference?

Answer 41

9. By reference.

Question 42

10. When you pass an array name as an argument to a function, what is actually being
    passed?

Answer 42

passing array name to function will pass address of array of integers

Question 43

11. How do you establish a parallel relationship between two or more arrays?

Answer 43

11. By using the same subscript value for each array.

Question 44

12. Look at the following array definition.
    double sales[8][10];
    How many rows does the array have?
    How many columns does the array have?
    How many elements does the array have?
    Write a statement that stores a number in the last column of the last row in the array.

Answer 44

double sales[8][10];

array has 8 rows
array has 10 columns
array has 80 elements

sales[7][9]=52.61, stores the number in the last column of the last row in the array

Question 45

13. When writing a function that accepts a two-dimensional array as an argument, which
    size declarator must you provide in the parameter for the array?

Answer 45

13. The second size declarator, which is for the number of columns.

Question 46

14. What advantages does a vector offer over an array?

Answer 46

1. you do not have to declare the number of elements that a vector will have;
2. if you add a value to a vector that is already full, the vector will automatically increase its size to accommodate the new data

Question 47

Fill-in-the-Blank

15. The _________ indicates the number of elements, or values, an array can hold.

Answer 47

15. size declarator

Question 48

16. The size declarator must be a(n) _________ with a value greater than _________.

Answer 48

integer / zero

Question 49

17. Each element of an array is accessed and indexed by a number known as a(n)
    _________.

Answer 49

17. subscript

Question 50

18. Subscript numbering in C++ always starts at _________.

Answer 50

zero

Question 51

19. The number inside the brackets of an array definition is the _________, but the number
    inside an array s brackets in an assignment statement, or any other statement that
    works with the contents of the array, is the _________.

Answer 51

19. size declarator, subscript

Question 52

20. C++ has no array _________ checking, which means you can inadvertently store data
    past the end of an array.

Answer 52

bounds

Question 53

21. Starting values for an array may be specified with a(n) _________ list.

Answer 53

21. initialization

Question 54

22. If an array is partially initialized, the uninitialized elements will be set to _________.

Answer 54

zero

Question 55

23. If the size declarator of an array definition is omitted, C++ counts the number of items
    in the _________ to determine how large the array should be.

Answer 55

23. initialization list

Question 56

24. By using the same _________ for multiple arrays, you can build relationships between
    the data stored in the arrays.

Answer 56

subscript

Question 57

25. You cannot use the _________ operator to copy data from one array to another in a
    single statement.

Answer 57

25. =

Question 58

26. Any time the name of an array is used without brackets and a subscript, it is seen as
    _________.

Answer 58

array’s beginning memory address

Question 59

27. To pass an array to a function, pass the _________ of the array.

Answer 59

27. address, or name

Question 60

28. A(n) _________ array is like several arrays of the same type put together.

Answer 60

two dimensional

Question 61

29. It s best to think of a two-dimensional array as having _________ and _________.

Answer 61

29. rows, columns

Question 62

30. To define a two-dimensional array, _________ size declarators are required.

Answer 62

two

Question 63

31. When initializing a two-dimensional array, it helps to enclose each row s initialization
    list in _________.

Answer 63

31. braces

Question 64

32. When a two-dimensional array is passed to a function the _________ size must
    be specified.

Answer 64

column

Question 65

33. The ____________________ is a collection of programmer-defined data types and
    algorithms that you may use in your programs

Answer 65

33. Standard Template Library (or STL)

Question 66

34. The two types of containers defined by the STL are ___________ and
    ______________.

Answer 66

sequence containers / associative containers

Question 67

35. The vector data type is a(n) ______________ container.

Answer 67

35. sequence

Question 68

36. To define a vector in your program, you must #include the ____________ header
    file.

Answer 68

vector

Question 69

37. To store a value in a vector that does not have a starting size, or that is already full,
    use the ________________ member function.

Answer 69

37. push_back

Question 70

38. To determine the number of elements in a vector, use the _____________ member
    function.

Answer 70

size

Question 71

39. Use the ________________ member function to remove the last element from a vector.

Answer 71

39. pop_back

Question 72

40. To completely clear the contents of a vector, use the ___________ member function.

Answer 72

clear

Question 73

Algorithm Workbench
41. names is an integer array with 20 elements. Write a for loop that prints each element
of the array.

Answer 73

41. for (int i = 0; i < 20; i++)

cout &laquo_space;names[i] &laquo_space;endl;

Question 74

42. The arrays numberArray1 and numberArray2 have 100 elements. Write code that
    copies the values in numberArray1 to numberArray2.

Answer 74

const int size = 100;
for(int i =0; i<size;i++)
numberArray2[i] = numberArray1[i]

Question 75

43. In a program you need to store the identification numbers of 10 employees (as ints)
    and their weekly gross pay (as doubles).
    A) De ne two arrays that may be used in parallel to store the 10 employee identi cation
    numbers and gross pay amounts.
    B) Write a loop that uses these arrays to print each employee s identi cation number
    and weekly gross pay.

Answer 75

43. const int SIZE = 10;
int id[SIZE]; // To hold ID numbers
double weeklyPay[SIZE]; // To hold weekly pay
// Display each employee's gross weekly pay.
for (int i = 0; i

Question 76

44. Define a two-dimensional array of integers named grades. It should have 30 rows
    and 10 columns.

Answer 76

int grades[30][10];

Question 77

45. In a program you need to store the populations of 12 countries.
    A) Define two arrays that may be used in parallel to store the names of the countries
    and their populations.
    B) Write a loop that uses these arrays to print each country s name and its population.

Answer 77

45. const int SIZE = 12;
// A string array to hold the country names
string countries[SIZE];
// An array to hold populations
long populations[SIZE];
// Display each country's name and population.
for (int i = 0; i

Question 78

46. The following code totals the values in two arrays: numberArray1 and
    numberArray2. Both arrays have 25 elements. Will the code print the correct sum of
    values for both arrays? Why or why not?
    int total = 0; // Accumulator
    int count; // Loop counter
    // Calculate and display the total of the first array.
    for (count = 0; count

Answer 78

see

Question 79

47. Look at the following array definition.
    int numberArray[9][11];
    Write a statement that assigns 145 to the rst column of the rst row of this array.
    Write a statement that assigns 18 to the last column of the last row of this array.

Answer 79

47. numberArray[0][0] = 145;

numberArray[8][10] = 18;

Question 80

48.
values
is a two-dimensional array of
float
s with 10 rows and 20 columns. Write
code that sums all the elements in the array and stores the sum in the variable
total
.

Answer 80

int row, col;
float total = 0.0;

for (row = 0; row < 10; row ++)
{
for(col = 0; col <20; col++)
total +=value[row][col];

Question 81

49. An application uses a two-dimensional array defined as follows.
    int days[29][5];
    Write code that sums each row in the array and displays the results.
    Write code that sums each column in the array and displays the results.

Answer 81

49. const int NUM_ROWS = 29;
const int NUM_COLS = 5;
int row, col, // Loop counters
total; // Accumulator
// Display the sum of each row.
for (row = 0; row

Question 82

True or False

50. T F An array s size declarator can be either a literal, a named constant, or a variable.

Answer 82

f
as array size declarator must be a constant integer expression with a value greater than zero. it can be either a literal or a named constant

Question 83

51. T F To calculate the amount of memory used by an array, multiply the number of
    elements by the number of bytes each element uses.

Answer 83

t

Question 84

52. T F The individual elements of an array are accessed and indexed by unique
    numbers.

Answer 84

t

Question 85

53. T F The first element in an array is accessed by the subscript 1.

Answer 85

f

Question 86

54. T F The subscript of the last element in a single-dimensional array is one less than
    the total number of elements in the array.

Answer 86

t

Question 87

55. T F The contents of an array element cannot be displayed with
    cout
    .

Answer 87

f

Question 88

56. T F Subscript numbers may be stored in variables.

Answer 88

t

Question 89

57. T F You can write programs that use invalid subscripts for an array.

Answer 89

t

Question 90

58. T F Arrays cannot be initialized when they are defined. A loop or other means must
    be used.

Answer 90

f

as array can be initialized when they are defined

Question 91

59. T F The values in an initialization list are stored in the array in the order they
    appear in the list.

Answer 91

t

Question 92

60. T F C++ allows you to partially initialize an array.

Answer 92

t

Question 93

61. T F If an array is partially initialized, the uninitialized elements will contain
    “garbage”.

Answer 93

f

Question 94

62. T F If you leave an element uninitialized, you do not have to leave all the ones that
    follow it uninitialized.

Answer 94

f

all the elements followed it are un initialized as will

Question 95

63. T F If you leave out the size declarator of an array definition, you do not have to
    include an initialization list.

Answer 95

f

Question 96

64. T F The uninitialized elements of a
string
array will automatically be set to the
value
"0"
.

Answer 96

t

Question 97

65. T F You cannot use the assignment operator to copy one array s contents to
    another in a single statement.

Answer 97

t

Question 98

66. T F When an array name is used without brackets and a subscript, it is seen as the
    value of the first element in the array.

Answer 98

f

an array name without brackets and a subscript indicates array’s beginning memory address

Question 99

67. T F To pass an array to a function, pass the name of the array.

Answer 99

t

Question 100

68. T F When defining a parameter variable to hold a single-dimensional array argument,
    you do not have to include the size declarator.

Answer 100

f

as size declarator must be specified in order to process elements in function

Question 101

69. T F When an array is passed to a function, the function has access to the original
    array.

Answer 101

t

Question 102

70. T F A two-dimensional array is like several identical arrays put together.

Answer 102

t

Question 103

71. T F It s best to think of two-dimensional arrays as having rows and columns.

Answer 103

t

Question 104

72. T F The first size declarator (in the declaration of a two-dimensional array) represents
    the number of columns. The second size definition represents the number
    of rows.

Answer 104

f, as first size declarator represents the number of rows and second represents the number of columns

Question 105

73. T F Two-dimensional arrays may be passed to functions, but the row size must be
    specified in the definition of the parameter variable.

Answer 105

f

Question 106

74. T F C++ allows you to create arrays with three or more dimensions.

Answer 106

t

Question 107

75. T F A vector is an associative container.

Answer 107

f

Question 108

76. T F To use a vector, you must include the vector header file.

Answer 108

t

Question 109

77. T F vectors can report the number of elements they contain.

Answer 109

t

Question 110

78. T F You can use the [] operator to insert a value into a vector that has no elements.

Answer 110

f

only using function push_back(value) we can insert data to vector

Question 111

79. T F If you add a value to a vector that is already full, the vector will automatically
    increase its size to accommodate the new value.

Answer 111

t

Question 112

Find the Error
Each of the following definitions and program segments has errors. iLocate as many as you can.
80. int size;
double values[size];

Answer 112

must be provided with initial value and used in next statement

Question 113

81. int collection[-20];

Answer 113

81. The size declarator cannot be negative.

Question 114

82. int table[10];
for (int x = 0; x < 20; x++)
{
cout << "Enter the next value: ";
cin >> table[x];
}

Answer 114

invalid access of array

Question 115

83. int hours[3] = 8, 12, 16;

Answer 115

83. The initialization list must be enclosed in braces.

Question 116

84. int numbers[8] = {1, 2, , 4, , 5};

Answer 116

two of initialization values are left out

Question 117

85. float ratings[];

Answer 117

85. For the array to be implicitly sized there must be an initialization list.

Question 118

86. char greeting[] = {‘H’, ‘e’, ‘l’, ‘l’, ‘o’};

cout &laquo_space;greeting;

Answer 118

a null terminator must be specified in the intialization list

Question 119

87. int array1[4], array2[4] = {3, 6, 9, 12};

array1 = array2;

Answer 119

87. The assignment operator cannot be used to assign the contents of one array to another, in a
    single statement.

Question 120

88. void showValues(int nums)
{
for (int count = 0; count < 8; count++)
cout << nums[count];
}

Answer 120

the function should have a parameter to hold array elements and size parameter must also be there

Question 121

89. void showValues(int nums[4][])
{
for (rows = 0; rows < 4; rows++)
for (cols = 0; cols < 5; cols++)
cout << nums[rows][cols];
}

Answer 121

89. The parameter must specify the number of columns, not the number of rows.