How to append to a file in C++?

Question

I want to print some data to a file with a few separate calls. I noticed that the default behaviour for a write overwrites the previously written data.

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

void hehehaha (){
  ofstream myfile;
  myfile.open ("example.txt");
  myfile << "Writing this to a file.\n";
  myfile.close();   
}

int main () {
  for(int i = 0; i < 3 ; i++) {
    hehehaha();
  }
  return 0;
}

this code writes only one line Writing this to a file. but what I want is the following:

Writing this to a file.
Writing this to a file.
Writing this to a file.

Answer 1

Open the file in app mode instead myfile.open("example.txt", std::ios_base::app);