如何将列名设置为csv文件 - c ++

Question

I am writing some string data to a .csv file using ofstream like

out << string-A << "," <<  string-B << "\n" ;

But, I could not find a way to set the column name of the .csv file.

I mean, I want to give column name of string-A to (say) Col-1 and string-B to (say) Col-2.

How to do that in c++ (I don't want to use any libraries). I am working in windows environment.

Edit: I want format like:

Col-1         col-2
1              4
2              5
3              6
4              7

Column names are headings not cell values ?

Answer 1

你可以先这样做：

out << setiosflags(ios::left) << setw（20）<< "ROW-1" << setiosflags(ios::left) << setw(20) << "ROW-2" << "\n";

Answer 2

out << "Col-1" << "," << "col-2" << "\n";
out << "1"     << "," << "4"     << "\n";
out << "2"     << "," << "5"     << "\n";
out << "3"     << "," << "6"     << "\n";
out << "4"     << "," << "7"     << "\n";

Since it is a text file you can write every line, independent of the data (ie if it is a header/column name or data row).

However, high likely you want to write the data as a loop, something like:

out << "Col-1" << "," << "col-2" << "\n";
for (var x = 1; x < 5; x++)
{
    out << x.ToString() << "," << (x + 3).ToString() << "\n";
}

Also when reading the data, you want to skip the colum names. To do this, you can skip the first line by default, or you use a 'comment' character like # and skip it dynamically. In this case the output of the file should look like:

#Col-1         col-2
1              4
2              5
3              6
4              7

and the code to produce this:

out << "#Col-1" << "," << "col-2" << "\n";
for (var x = 1; x < 5; x++)
{
    out << x.ToString() << "," << (x + 3).ToString() << "\n";
}

Answer 3

You can write the names just like you the writing the data. You will have to do this at start. However depending upon the width of data string you will need to do some formatting so that data is correctly aligned below Col-1 and Col-2.

out <<"Col-1"<< " "<<"Col-2"<< "\n" ;