Question:
In C, I use the FILE *filename. As a beginning C++ programmer, I open streams for reading and writing inside the main() function, but when I try to work with the open files inside another function, it can’t reference the original files.

Answer:
The trick is to pass to the function a reference to the same object thatyou used to open the file in the first place.. Here is an example:

int main (){   ifsteam ifile (“somefile”);   readFile(ifile);}void readFile (ifsterm &if){  int i;  if >> i;  // any more operations on the stream}