A File is a bunch of bytes stored on some storage device like magnetic disk or tape etc. Most of the application programs process large volume of data which is permanently stored in files. We can write programs that can read data from file(s) and write data to file(s).
A Friend Function is a non-member function that can access private data’s. A friend CLASS is a class whose member functions can access another class i.e. private and protected classes.
Array is an arrangement of same type of data at adjacent memory locations. Array is useful whenever large volume of data is to be processed and stored in the memory.
Suppose an average marks are to be calculated from all the students in the school. This is difficult to find the sum of marks of all students. In this situation an array is the best alternative. Its divided in two categories:
1. Single / 1-D Array
2. Multi-dimension Array
