How to create a file using a C++ program

Overview

In C++, we use files to read and write data. In addition to this, files can also be created through C++.

C++ uses the fstream library to carry out file operations.

Code

We'll write a C++ program to create a file:

#include <iostream>
//include fstream for file oprations
#include <fstream>
 
using namespace std;
 
int main()
{
  fstream file; //object of fstream class
    
  //open file "test.txt" in out(write) mode
  // ios::out Open for output operations.
  file.open("test.txt",ios::out);
    
  //If file is not created, return error
  if(!file){
    cout<<"Error in file creation!";
    return 0;
  }else{ //File is created
    cout<<"File Creation successfull.";
  }
  //closing the file
  file.close();
    
  return 0;
}

Explanation

  • Lines 1 to 8: We include fstream to enable file operations and an fstream object is declared.
  • Line 13: We create a file in the file.open() statement by passing the file's name to be created in the parameter, along with ios::out, which enables this file for output operations.
  • Lines 16 to 24: We check whether the file creation is successful or not, and it returns the output accordingly.
  • Line 26: We use file.close() to close the file. This is important to prevent data loss.
Note: The file won't be created if the file is opened in input mode. It is only created if the file is opened in either output mode or append mode.

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