[c++] clear data inside text file in c++

I am programming on C++. In my code I create a text file, write data to the file and reading from the file using stream, after I finish the sequence I desire I wish to clear all the data inside the txt file. Can someone tell me the command to clear the data in the txt file. Thank you

If you simply open the file for writing with the truncate-option, you'll delete the content.

std::ofstream ofs;
ofs.open("test.txt", std::ofstream::out | std::ofstream::trunc);
ofs.close();

http://www.cplusplus.com/reference/fstream/ofstream/open/

Deleting the file will also remove the content. See remove file.

If you set the trunc flag.

#include<fstream>

using namespace std;

fstream ofs;

int main(){
ofs.open("test.txt", ios::out | ios::trunc);
ofs<<"Your content here";
ofs.close(); //Using microsoft incremental linker version 14
}

I tested this thouroughly for my own needs in a common programming situation I had. Definitely be sure to preform the ".close();" operation. If you don't do this there is no telling whether or not you you trunc or just app to the begging of the file. Depending on the file type you might just append over the file which depending on your needs may not fullfill its purpose. Be sure to call ".close();" explicity on the fstream you are trying to replace.

As far as I am aware, simply opening the file in write mode without append mode will erase the contents of the file.

ofstream file("filename.txt"); // Without append
ofstream file("filename.txt", ios::app); // with append

The first one will place the position bit at the beginning erasing all contents while the second version will place the position bit at the end-of-file bit and write from there.