file_handling.cpp

#include <iostream>
#include <fstream>
using namespace std;

int main() {
  ofstream MyFile;
  // open the file
  MyFile.open("test.txt");

  MyFile << "Some text. \n";
  // close the file.
  MyFile.close();
}

Under certain circumstances, such as when you don't have file permissions, the open function can fail.
The is_open() member function checks whether the file is open and ready to be accessed.

#include <iostream>
#include <fstream>
using namespace std;

int main() {
  ofstream MyFile("test.txt");

  if (MyFile.is_open()) {
   MyFile << "This is awesome! \n";
  }
  else {
   cout << "Something went wrong";
  }
  MyFile.close();
}

Reading information from the file, line by line.

#include <iostream>
#include <fstream>
using namespace std;

int main () {
    ofstream MyFile1("test.txt");
    
    MyFile1 << "This is awesome! \n";
    MyFile1.close();

    string line;
    ifstream MyFile("test.txt");
    while ( getline (MyFile, line) ) {
        cout << line << '\n';
    }
    MyFile.close();
}