Question

1. what header file do you need to include in a program that performs file operations?
2. what data type do you use when you want to create a file stream object that can write data to a file?
3. what data type do you use when you want to create a file stream object that can read data from a file?
4. why should a program close a file when its finished using it?

Explanation:

1. In C++, for file operations, <fstream> header file is included which provides definitions for file - stream classes.
2. In C++, ofstream (output file stream) data type is used to create an object that can write data to a file.
3. In C++, ifstream (input file stream) data type is used to create an object that can read data from a file.
4. Closing a file when done using it releases system resources associated with the file, flushes any unwritten data to the file to ensure data integrity, and allows other programs to access the file if needed.

Answer:

1. <fstream>
2. ofstream
3. ifstream
4. To release resources, ensure data integrity, and allow other programs to access the file.