9. Streams (IC)

Question 1

What is the purpose of the following code snippet?
ifstream inputFile(inputFileName); if (!inputFile.is_open()) { cout &laquo_space;“Failed to open the input file.” &laquo_space;endl; return 1; }
A) Opens the input file for reading B) Checks if the input file exists C) Outputs an error message if the input file failed to open D) Terminates the program with an error code if the input file failed to open

Answer 1

A) Opens the input file for reading

Question 2

What is the purpose of the size_t data type used in the loops? A) Storing the movie titles B) Storing the ratings C) Storing the showtimes D) Storing the sizes of containers

Answer 2

D) Storing the sizes of containers

Question 3

How can you open a file for reading using ifstream? a) file.open(“filename.txt”, ios::out) b) file.open(“filename.txt”, ios::in) c) file.open(“filename.txt”, ios::app) d) file.open(“filename.txt”, ios::binary)

Answer 3

b) file.open(“filename.txt”, ios::in)

Question 4

Which header file should be included to use ifstream and ofstream classes for file input and output? a) <iostream> b) <fstream> c) <string> d) <sstream></sstream></string></fstream></iostream>

Answer 4

b) <fstream></fstream>

Question 5

What is the purpose of the input stream object in C++? a) Read input from the console b) Write output to the console c) Perform mathematical calculations d) Manipulate string data

Answer 5

a) Read input from the console

Question 6

// Compute the average exam score and assign a letter grade double average = XXXXXXXXXX = assignLetterGrade(average); letterGrades.push_back(grade);
A) (midterm1 + midterm2 + final) / 3.0 B) (midterm1 + midterm2) / 2.0 C) (midterm1 + final) / 2.0 D) (midterm2 + final) / 2.0

Answer 6

A) (midterm1 + midterm2 + final) / 3.0

Question 7

if (!found) { movieTitles.push_back(title.substr(0, 44)); movieRatings.push_back(rating); showtimes.push_back({ title, showtime }); } } inputFile.close();
How are the movie titles truncated to a maximum of 44 characters? A) Using the substr function B) Using the find function C) Using the getline function D) Using the setw manipulator

Answer 7

A) Using the substr function

Question 8

for (size_t i = 0; i < showtimes.size(); i++) {
cout &laquo_space;left &laquo_space;setw(44) &laquo_space;movieTitles[i] &laquo_space;” | “ &laquo_space;right &laquo_space;setw(5) &laquo_space;movieRatings[i] &laquo_space;” | “;
for (size_t j = 1; XXXXXXX; j++) {
cout &laquo_space;showtimes[i][j];
if (j != showtimes[i].size()-1) {
cout &laquo_space;” “;
}
}
cout &laquo_space;endl;
}
return 0;
}
A) i < showtimes.size() B) j < showtimes[i].size() C) j != showtimes[i].size()-1 D) movieShowtimes[0] == title

Answer 8

B) j < showtimes[i].size()

Question 9

ostream

Answer 9

short for “output stream,” is a class that supports output, available via #include <iostream> and in namespace"std".</iostream>

Question 10

insertion operator

Answer 10

«

Question 11

istream

Answer 11

short for “input stream,” is a class that supports input. Available via#include <iostream></iostream>

Question 12

manipulator

Answer 12

a function that overloads the insertion operator &laquo_space;or extraction operator&raquo_space; to adjust the way output appears.

Question 13

istringstream

Answer 13

reads input from an associated string instead of the keyboard

Question 14

eof()

Answer 14

returns true or false depending on whether or not the end of the stream has been reached.

Question 15

ostringstream

Answer 15

insert characters into a string bufferinstead of the screen

Question 16

fail()

Answer 16

returns true if the previous stream operation had an error.

Question 17

stream error

Answer 17

occurs when insertion or extraction fails, causing the stream to enter an errorstate.

Question 18

ofstream

Answer 18

short for “output file stream”, is a class that supports writing to a file.

Question 19

extraction operator

Answer 19

> >

Question 20

ifstream inputFile(inputFileName);
if (!inputFile.is_open()) {
cout &laquo_space;“Failed to open the input file.” &laquo_space;endl;
return 1;
}

What does if (!inputFile.is_open()) check? a) If the input file is open b) If the input file failed to open c) If the input file is empty d) If there was an error while reading the input file

Answer 20

b) If the input file failed to open

Question 21

Which library is used for basic input and output operations in C++? a) iostream b) string c) fstream d) sstream

Answer 21

a) iostream

Question 22

The getline() function is used to read a __________ from an input stream.

Answer 22

line

Question 23

The&raquo_space; operator is used for __________ from an input stream.

Answer 23

extraction

Question 24

The stringstream class can be used to manipulate __________.

Answer 24

strings

Question 25

What does the eof() function in C++ check for? a) Check if the input stream is in a fail state b) Check if the end of the file has been reached c) Check if a specific character is found in the input stream d) Check if the input stream is empty

Answer 25

b) Check if the end of the file has been reached

Question 26

What does the following line of code do? int day = stoi(date.substr(date.find(‘ ‘) + 1, date.find(‘,’) - date.find(‘ ‘) - 1));
A) Extracts the day from the input date string B) Extracts the year from the input date string C) Converts the day string to an integer D) Converts the year string to an integer

Answer 26

A) Extracts the day from the input date string

Question 27

What is the purpose of the following line of code? string month = date.substr(0, date.find(‘ ‘));
A) Extract the day from the input date B) Extract the month from the input date C) Extract the year from the input date D) Extract the month and day from the input date

Answer 27

B) Extract the month from the input date