Chapter 12, Problem 1RQE

What capability does the fstream data type provide that the ifstream and ofstream data types do not?

Explanation of Solution

Header file used to perform file operations:

“fstream” (file stream) is the standard header file in C++ used to perform file operations such as file creation, write information to the file and read information from the file.

ofstream:

“ofstream” is a data type that represents output file stream used to create files and write information to files using output file stream object.

A file where the data are written is called as output file. When a program stores the output in a file, then it is called as output file.

ifstream:

“ifstream” is a data type that represents input file stream used to read information from files using input file stream object.

A file from which the data is read is called as input file. When a program gets input from the file, then it is called as input file.

Therefore, the data type “fstream” performs both read and write operation whereas the data type “ifstream” will perform only a read operation and the data type “ofstream” performs the write operation.

Example program:

The below code is an example for the “ifstream” usage to read information from file: 

//Include the necessary header files

#include <iostream>

//Header file used to perform “file operations”

#include <fstream>

#include<string>

using namespace std;

// Main function

int main()

{

string str= "sample.txt";

//Create object for ofstream

ofstream out(str.data());

/*Write information to the file using ofstream object “out”*/

out << "Welcome to file operation";

//Close the file

out.close();

//Create object for ifstream

ifstream in(str.data());

/*Read the information from file until it reaches end of file*/

while (!in.eof())

{

in >> line;

cout << line;

}

//Newline

cout << endl;

//Close the file

in.close();

// Return statement

return 0;

}

Sample Output

Note: Write the information to the file using “ofstream” object.

Screenshot of “sample.txt” file

Note: Read the information from the file using “ifstream” object.

Screenshot of output file