cap 5-8

Question 1

In the following function, what is passed to the first parameter?

void f1( int& value1, int value2);

int x,y;
f1(x,y);

a. The value of x
b. nothing, it is a void function
c. the value of y
d. the variable x (or its memory location)

Answer 1

the variable x (or its memory location)

Question 2

Given the following function definitions and program fragments, what is the output?

void f1(int& z, int &q)
{
int temp;
temp=q;
q=z;
z=temp;
}

void f2( int& a, int& b)
{
if( a<b)
f1(a,b);
else
a=b;
}

int x=3, y=4;
f2(y,x);
cout &laquo_space;x «” “ &laquo_space;y &laquo_space;endl;

a. 3 3
b. 4 3
c. 3 4
d. 4 4

Answer 2

3 3

Question 3

A simplified version of a function which is used to test the main program is called
a. A stub
b. Abstraction
c. Polymorphism
d. A driver

Answer 3

A stub

Question 4

A simplified main program used to test functions is called
a. A stub
b. Abstraction
c. Polymorphism
d. A driver

Answer 4

A driver

Question 5

Testing a function or program using test values that are at or near the values that change the outcome of the program is known as using
a. parameters
b. functional decomposition
c. boundary values
d. a black-box

Answer 5

boundary values

Question 6

Call-by-reference should be used
a. For all variables
b. When the function needs to change the value of one or more arguments
c. Never
d. only in void functions

Answer 6

When the function needs to change the value of one or more arguments

Question 7

Which of the following comments would be the best post-condition for this swap function void swap( int& left, int&right);
a. //Postcondition: None
b. //Postcondition: the values of left and right are exchanged.
c. //Postcondition: left has the value of right
d. //Postcondition: left and right are unchanged

Answer 7

//Postcondition: the values of left and right are exchanged.

Question 8

What is wrong with the following code?
int f1( int x, int y)
{
x = y * y;
return x;

int f2( float a, float& b)
{
if(a < b)
b = a;
else
a=b;
return 0.0;
}
}
a. Neither function should return a value
b. Function definitions may not be nested
c. Both parameters to f2 should be pass-by reference
d. in f2, a can not be assigned b.
e. nothing is wrong

Answer 8

Function definitions may not be nested

Question 9

If you write a function that should use call-by-reference, but forget to include the ampersand,
a. The program will not compile
b. The program will not link
c. The program will not run without a run-time error
d. The program will run with incorrect results
e. It doesn’t matter

Answer 9

The program will run with incorrect results

Question 10

Testing your program should be done
a. As each function is developed
b. At the end of the coding
c. Only if there appear to be problems
d. Only if your instructor requires it.

Answer 10

As each function is developed

Question 11

Which of the following is not used when using files for input and output
a. Opening the file stream
b. Ensuring that the stream opened
c. Closing the stream
d. Prompting for file data

Answer 11

Prompting for file data

Question 12

Which include directive is necessary for file IO
a. #include <fstream>
b. #include <iomanip>
c. #include <cstdlib>
d. #include <fileIO></fileIO></cstdlib></iomanip></fstream>

Answer 12

include <fstream></fstream>

Question 13

Which statement correctly opens an input stream named in_file and attaches it to a file name project.txt?
a. in_file=project.txt
b. in_file=”project.txt”
c. in_file.open(“project.txt”);
d. in_file.open(project.txt);

Answer 13

in_file.open(“project.txt”);

Question 14

When is the external name of the file used in the program?
a. Any time you read or write to the file
b. Never
c. Only when reading from the file
d. When opening the file stream

Answer 14

When opening the file stream

Question 15

A __________ is a variable that has functions as well as data associated with it.
a. member
b. int
c. object
d. float

Answer 15

object

Question 16

A function that is associated with an object is called a _________ function.
a. input
b. output
c. member
d. instantiated

Answer 16

member

Question 17

Which of the following is the correct way to close a file stream named outFile?
a. outFile.close();
b. outFile.close;
c. outFile.close(“project.txt”);
d. close(outFile);

Answer 17

outFile.close();

Question 18

After a stream is opened, before it is used for input and output, it should be
a. declared
b. closed
c. checked to see if it opened correctly
d. none of the above

Answer 18

checked to see if it opened correctly

Question 19

Which of the following is the correct way to determine if a file stream named inFile opened correctly?
a. if( inFile.open() )
b. if( inFile.fail() )
c. if( inFile.opened() )
d. if( inFile.failed() )

Answer 19

if( inFile.fail() )

Question 20

If a file did not open correctly, you should
a. continue on anyway
b. display an error message and continue on
c. display an error message and take some suitable action such as exit
d. exit the program immediately

Answer 20

display an error message and take some suitable action such as exit

Question 21

What are the valid indexes for the array shown below?
int myArray[25];

0-25
0-24
1-25
1-24

Answer 21

0-24

Question 22

What is wrong with the following code?
float scores[10], total;

Cannot declare regular and array variables together.
Arrays must be integers
The 10 should be replaced with a variable name, whose value is input from the user
Nothing.

Answer 22

Nothing.

Question 23

Given an array named scores with 25 elements, what is the correct way to access the 25th element?
scores+25
scores[24]
scores[25]
scores[last]

Answer 23

scores[24]

Question 24

Why should you use a named constant for the size of an array?
Readability of code
Makes changes to the program easier
Helps reduce logic errors
All of the above

Answer 24

All of the above

Question 25

Given an array of integers of size 5, how does the computer know where the 3rd indexed variable is located?
It adds 3 to the base address of the array
It adds space for 3 integers to the base address of the array
It remembers where all the indexed variables of the array are located.
None of the above

Answer 25

It adds space for 3 integers to the base address of the array

Question 26

What is wrong with the following code fragment?
const int SIZE =5;

float scores[SIZE];

for(int i=0; i<=SIZE;i++)

{

        cout << "Enter a score\n";

        cin >> scores[i];

}

Array indexes start at 1 not 0
Arrays must be integers
Array indexes must be less than the size of the array
Should be cin&raquo_space; scores[0];

Answer 26

Array indexes must be less than the size of the array

Question 27

Which of the following declare an array of 5 characters, and initializes them to some known values?
char array[5]={‘a’,’b’,’c’,’d’,’e’};
char array[4]={‘a’,’b’,’c’,’d’,’e’};
char array[5]={‘’};
char array[]={‘a’,’b’,’d’,’e’};
A and C
B and D
all of the above

Answer 27

char array[5]={‘a’,’b’,’c’,’d’,’e’}; and char array[5]={‘’};

Question 28

If you declare and initialize an integer array of size 10, but only list 5 values, what values are stored in the remaining 5 indexed variables?
0
garbage
0.0
‘0’

Answer 28

garbage

Question 29

Arrays are always passed to a function using
pass by value
pass by reference
pass by numbers
you cannot pass arrays to a function

Answer 29

pass by numbers

Question 30

Give the following declarations, which of the following is a legal call to this function?
int myFunction(int myValue);

int myArray[1000];

cout &laquo_space;myFunction(myArray);
cout &laquo_space;myFunction(myArray[0]);
myArray = myFunction(myArray);
myArray[1] = myFunction(myArray[0]);
A and B
A and C
B and D

Answer 30

cout &laquo_space;myFunction(myArray[0]); and myArray[1] = myFunction(myArray[0]);

Question 31

Which of the following function declarations correctly expect an array as the first argument?
void f1(int array, int size);
void f1(int& array, int size);
void f1(int array[100], int size);
void f1(float array[], int size);
All of the above
C and D
A and B

Answer 31

void f1(int array[100], int size); and void f1(float array[], int size);

Question 32

Which of the following function declarations correctly guarantee that the function will not change any values in the array argument?
void f1(int array[], int size) const;
void f1(int array[], int size);
void f1(int &array, int size);
void f1(const int array[], int size);
void f1(int array[], const int size);

Answer 32

void f1(const int array[], int size);

Question 33

The following function definition has an error in it. What line is this error on?
0. void f1(const double array[], int size)

1. {
2. int i=0;
3. while(i< size)
4. {
5. array[i] += 2;
6. cout «array[i];
7. i++;
8. }
9. }

0
2
5
6
2

Answer 33

5

Question 34

Which of the following function declarations could be used to input data from the keyboard into the array?
void input(int array[], int &numElements, int MAX_SIZE);
void input(int array[], int numElements, int MAX_SIZE);
void input(int &array[], int numElements, int MAX_SIZE);
int array[] input(int array[], int &numElements, int MAX_SIZE);

Answer 34

void input(int array[], int &numElements, int MAX_SIZE);

Question 35

If we want a search function to search an array for some value and return either the index where the value was found, or -1 if not found, which of the following prototypes would be appropriate?
void search(const int array, int target, int numElements);
void search(const int array, int target);
int search(const int array[], int numElements);
int search(const int array[], int target, int numElements);

Answer 35

int search(const int array[], int target, int numElements);

Question 36

Given the following function definition for a search function, and the following variable declarations, which of the following are appropriate function invocations?

const int SIZE=1000;

int search(const int array[], int target, int numElements);

int array[SIZE], target, numberOfElements;

search(array[0], target, numberOfElements);
result=search(array[0], target, numberOfElements);
result=search(array, target, numberOfElements);
result=search(array, target, SIZE);

Answer 36

result=search(array, target, numberOfElements);

Question 37

Given the following function definition, will repeated calls to the search function for the same target find all occurrences of that target in the array?
int search(const int array[], int target, int numElements)

{

        int index=0;

        bool found=false;

       

        while((!found) && (index < numElements))

        {

                    if(array[index] == target)

                                found=true;

                    else

                                index++;

        }

        if(found==true)

                    return index;

        else

                    return -1;

}

Yes
No
Impossible to tell without looking at the values of the array
It depends on the value of target.

Answer 37

No

Question 38

Given the following function definition, what modifications need to be made to the search function so that it finds all occurrences of target in the array?
int search(const int array[], int target, int numElements)

{

        int index=0;

        bool found=false;

       

        while((!found) && (index < numElements))

        {

                    if(array[index] == target)

                                found=true;

                    else

                                index++;

        }

        if(found==true)

                    return index;

        else

                    return -1;

}

Add another parameter to indicate where to stop searching
Add another parameter to indicate where to start searching
This already can find all occurrences of a given target
Have the function return the whole array

Answer 38

Add another parameter to indicate where to start searching

Question 39

Which sort algorithm does the following outline define?
for i between 0 and number_used-1 inclusive

        put the ith smallest element at array[i]

sequential
selection
bubble
swap

Answer 39

selection

Question 40

Which of the following array declarations are legal?
int array[10];
int size;
cin&raquo_space; size;

int array[size];

int array[]={0,0,0};
const int size=9;
int array[size];

All of the above
All but C
All but B

Answer 40

int array[]={0,0,0};

Question 41

A character array terminated with the null character is most correctly called
a c-string
a character array
a string
none of the above

Answer 41

a c-string

Question 42

Which of the following declarations correctly creates a c-string that can hold the value “phonebook”
char s1;
char s1[9];
char s1=10;
char s1[10];

Answer 42

char s1[10];

Question 43

To declare a c-string and initialize it to the value of “phonebook”,
char s1=phonebook;
char s1[10]=”phonebook”;
c-string phonebook;
char s1[10]=phonebook;

Answer 43

char s1[10]=”phonebook”;

Question 44

Which of the following will print out the value in str?
char str[30];

cin&raquo_space; str;

cout &laquo_space;str;
for(int i=0;i<30;i++)
cout &laquo_space;str[i];

int i=0;
while(i<30 && str[i] != ‘\0’)

        cout << str[i++];

All of the above
A and B
A and C

Answer 44

cin&raquo_space; str; and, int i=0;
while(i<30 && str[i] != ‘\0’)

        cout << str[i++];

Question 45

When the extraction operator is used to read data into a string,
it skips all white spaces
it skips only new lines
it reads everything on the line
it reads as many characters that will fit into the c-string

Answer 45

it skips all white spaces

Question 46

If you want to read into a c-string, you must ensure that the user does not enter more characters than
The size of the c-string
The size of the c-string + 1
The size of the c-string -1
It doesn’t matter.

Answer 46

The size of the c-string -1

Question 47

What is wrong with the following attempted c-string declaration and initialization?
char str1[5]={‘a’, ‘b’, ‘c’};

There are only 3 values in the braces
The single quotes should be double quotes
The values do not constitute a c-string
nothing

Answer 47

The values do not constitute a c-string

Question 48

How can you assign the value “toaster” to a c-string name str of size 10?
str=”toaster;
str=toaster;
strcpy(str,”toaster”);
str.strcpy(“toaster”);

Answer 48

strcpy(str,”toaster”);

Question 49

What is the difference between strcmp and strncmp?
No difference
they both compare, one expects an integer for the number of characters to compare.
one copies, the other compares
They are in different libraries

Answer 49

they both compare, one expects an integer for the number of characters to compare.

Question 50

strcmp(first, second) returns
<0 if first < second, 0 if first == second, positive otherwise
true if first=second, false otherwise
nothing, it’s a void function
>0 if first < second, 0 if first > second, <0 otherwise

Answer 50

<0 if first < second, 0 if first == second, positive otherwise

Question 51

What is wrong with the following code fragment?
char str1[10]=”Mark”, str2[15]=”What’s my name”;

strcpy(str1,str2);

Nothing
str2 has white space in it
str1 does not have enough room
str2 does not have enough room

Answer 51

str1 does not have enough room

Question 52

Which assignment statements will copy the value “ toaster” into a string variable (str1)?
strcpy(str1,”toaster”);
str1 = “toaster”;
str1 = toaster;
str1 += toaster;

Answer 52

str1 = “toaster”;

Question 53

What is the value of str after the following code?
string str;

a garbage string
the empty string
the null character
unknown

Answer 53

the empty string

Question 54

Which is the proper way to determine how many characters are in the string variable named str?
str.getLength()
str.length()
length(str)
getLength(str)

Answer 54

str.length()

Question 55

If the name of a file to open is in the string variable name fileName, which of the following will correctly open the file for output?
out_file.open(fileName);
out_file.open(“fileName”);
fileName.open(outfile);
out_file.open(fileName.c_str());

Answer 55

out_file.open(“fileName”);

Question 56

Which of the following would correctly read an entire line from an input file stream named fin into a string variable named line.
getline(fin, line);
fin.getline(line);
fin.getline(line,’\n');
fin.getline(line,80);

Answer 56

getline(fin, line);

Question 57

Which of the following returns the fourth character in the string variable named str and checks if there is a fourth character in the string?
str(3);
str.at(3);
str[3];
All of the above

Answer 57

str.at(3);

Question 58

Given the following declarations, which of the following is legal syntax?
string str=”Your name”;

  char c_string[20]="My name";

str = c_string;
c_string = str;
strcpy(c_string, str.c_str());
strcpy(c_string, str);
A and C

Answer 58

str = c_string; and strcpy(c_string, str.c_str());

Question 59

The notation vector<Base_Type> means that the vector is
an array
a template class
primitive data type
all of the above</Base_Type>

Answer 59

a template class

Question 60

The base type for a vector can be
int
float or double
char
any data type