I am learning output the data to a file using "ofstream". I need to read data from a file and output the result to the other file in 2 different ways. To do that I have to provoke two functions, and they have to output the result to the same text file. My problem is: they are correct on the screen (output first function and then the second), but when they output to the text file, the second one always erras or cover the first one.

I think it might because after the first function finished, the second function open the file again and output from the beginning. How can I make it begin from the end of first function's output?

Here is my code:

#include <iostream>

using namespace std;

void functionOne()
{
...
ofstream outfile("a.txt");

outfile << data << data ...;
}

void functionTwo()
{
...
ofstream outfile("a.txt");

outfile << data << data ...;
}

int main()
{
...
functionOne();
...
functionTwo();
...
return 0;
}

Replace ofstream outfile("a.txt"); in the second function with ofstream outfile("a.txt", ios::app);.

The default when you just include the filename is ios::out which overwrites the file if it exists.

Thanx, I got that already.