#include <iostream>

#include <fstream>

#include <string>

​

using namespace std;

​

void appendStringToFile(const string& textToAdd, const string& filename) {

    ofstream outFile(filename, ios::app); // Open the file in append mode

​

    if (outFile.is_open()) {

        outFile << textToAdd << endl;

        outFile.close();

​

        cout << "String appended to file '" << filename << "' successfully." << endl;

    } else {

        cout << "Error: Unable to open the file '" << filename << "'." << endl;

    }

}

​

int main() {

    string textToAdd = "This is new data appended to the file.";

    string filename = "output.txt";

​

    appendStringToFile(textToAdd, filename);

​

    return 0;

}