open and write to existing fstream without overwrite/clearing in C++

Question

I have an existing txt file, I want to be able to write stuff to it (on the next line) without modifying the existing contents. What's a good way to do this?

#include <iostream>
ofstream myfile ("ex.txt"); 

seems to clear all the existing text.

Answer 1

Open the file using the ios_base::app flag

Answer 2

ofstream myfile ("ex.txt", ios_base::app); will open a file in append mode. Each write operation will append to the existing contents.