QT ofstream use variable as a path name

Question

I'm trying to make a function which takes QString as well as an int. Convert QString variable into a filename for ofstream, then take the integer and place it into the file. So far I have managed to take a constant filename such as "Filename.dat" and write a variable into it. However when I try to use QString like this :

void write(const char what,int a){
    std::ofstream writefile;
    writefile.open("bin\\" + what);
    writefile << a;
    writefile.close();
}

I get an error

void write(const char,int)': cannot convert argument 1 from 'const char [5]' to 'const char

This is the function which calls write();

void Server::on_dial_valueChanged(int value)
{
    write("dial.dat",value);
}

When I use "bin\dial.dat" instead of combining "bin\" with a string it works fine. ofstream.open(); uses "const char*".

I've tried all the filetypes so they may not match my description

The question is- Does anybody have an idea how to combine "bin\" and a QString and make it work with ofstream? I've spend a lot of time googling it but still can't make it work. Thanks! Any suggestions are more than welcome

Answer 1

void write(const char what,int a) is wrong as you pass only one char to function you should have void write(const char* what,int a) to pass pointer to cstring beginning.

You also want to concat two cstrings and in c++ you can't do it like in other languages but you can use std::string to do what you want.

Try this

#include <string>

void write(const char* what,int a){
    std::ofstream writefile;
    std::string fileName("bin\\");
    fileName+=what;
    writefile.open(fileName.c_str());
    writefile << a;
    writefile.close();
}