Disappearing content c++ writing to file

Question

Whenever I write the data into the file after rerunning the code the contents of the file disappears

#include <iostream>
#include <fstream>

using namespace std;


int main(){
    string username = "";
    string path = "/Users/kishorejyothi/Desktop/C++/practice/list_usernames.txt";
    ofstream file(path);

    if(file.fail()){
        cerr << "Failed process";
        exit(1);
    }

    cout << "Enter a username: ";
    cin >> username;

    string full_username = username.append("@Abhinav.com");


    if(username.empty()){
        cout << "You didn't enter your username";
    }
    else{
        cout << "Thanks for entering your preferred username." << endl;
        cout << "Your username is now " << full_username;
    }
    file << username << endl;

    file.close();
}

I was exxpecting the file to write the usernames on seperaate lines of code.

Answer 1

the default open mode deletes the file content, open the file in append mode if you want it to keep its previous content.

ofstream file(path, std::ios::app);