Why file handling is required in C++ - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to open a file for reading.

C++

#include <fstream>
int main() {
    std::ifstream file[1];
    return 0;
}

Drag options to blanks, or click blank then click option'

A("data.txt")

B["data.txt"]

C{data.txt}

D<data.txt>

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets or braces instead of parentheses.

Not passing the filename as a string.

To open a file in C++, you use parentheses with the filename as a string.

2fill in blank

medium

Complete the code to write text to a file.

C++

#include <fstream>
int main() {
    std::ofstream file("output.txt");
    file[1] "Hello, file!";
    file.close();
    return 0;
}

Drag options to blanks, or click blank then click option'

A+=

B>>

C<<

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using >> instead of << for writing.

Using assignment operator = which is invalid here.

To write to a file stream, use the insertion operator <<.

3fill in blank

hard

Fix the error in the code to read a line from a file.

C++

#include <fstream>
#include <string>
int main() {
    std::ifstream file("input.txt");
    std::string line;
    if (file.is_open()) {
        std::getline(file[1], line);
    }
    return 0;
}

Drag options to blanks, or click blank then click option'

A)

B(

C;

D]

Attempts:

3 left

💡 Hint

Common Mistakes

Missing closing parenthesis.

Using brackets or semicolon instead of closing parenthesis.

The getline function requires the file stream as the first argument inside parentheses.

4fill in blank

hard

Fill both blanks to create a file and write multiple lines.

C++

#include <fstream>
int main() {
    std::ofstream file[1];
    file << "Line 1" << std::endl[2];
    file.close();
    return 0;
}

Drag options to blanks, or click blank then click option'

A("log.txt")

B("data.txt")

C<<

D>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong filename or wrong operator for writing.

Using >> instead of << for writing.

Use parentheses with filename to open file and << operator to write lines.

5fill in blank

hard

Fill both blanks to read from a file and print its content.

C++

#include <fstream>
#include <iostream>
#include <string>
int main() {
    std::ifstream file[1];
    std::string line;
    while (std::getline(file, line)) {
        std::cout[2] line << std::endl;;
    }
    file.close();
    return 0;
}

Drag options to blanks, or click blank then click option'

A("readme.txt")

B<<

C;

D>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using >> instead of << for output.

Missing semicolon at the end of the output statement.

Open file with filename in parentheses, use << to print, and end statement with semicolon.