what's the difference between opening a file with ios::binary or ios::out or both ?

Question

hello i'm trying to figure out the difference between opening a file like:

fstream *fileName*("FILE.dat",ios::binary);

or

fstream *fileName*("FILE.dat",ios::out);

or

fstream *fileName*("FILE.dat",ios::binary | ios::out);

i found that all of these forms are identical,i.e. in all cases ,the same output on the file is produced using either fileName<< or fileName.write()

so please tell me what is the real difference between them, i'm really confused!

THANKS

Answer 1

ios::out opens the file for writing.

ios::binary makes sure the data is read or written without translating new line characters to and from \r\n on the fly. In other words, exactly what you give the stream is exactly what's written.

Answer 2

Opening a file with ios::binary controls how newline characters are handled. On Windows, they are expanded to CRLF pairs. That's it - it has no effect on how things like operator<< work.

Answer 3

please make it clearer