Writing .csv files from C++

There is nothing special about a CSV file. You can create them using a text editor by simply following the basic rules. The RFC 4180 (tools.ietf.org/html/rfc4180) accepted separator is the comma ‘,’ not the semi-colon ‘;’. Programs like MS Excel expect a comma as a separator.

There are some programs that treat the comma as a decimal and the semi-colon as a separator, but these are technically outside of the “accepted” standard for CSV formatted files.

So, when creating a CSV you create your filestream and add your lines like so:

#include <iostream>
#include <fstream>
int main( int argc, char* argv[] )
{
      std::ofstream myfile;
      myfile.open ("example.csv");
      myfile << "This is the first cell in the first column.\n";
      myfile << "a,b,c,\n";
      myfile << "c,s,v,\n";
      myfile << "1,2,3.456\n";
      myfile << "semi;colon";
      myfile.close();
      return 0;
}

This will result in a CSV file that looks like this when opened in MS Excel: