Introduction

Today's lesson explains the fundamentals of file Input/Output. File I/O is used to represent the many different input and output operations that can be performed on a file, such as reading from the file or writing to the file. Accesing data via file I/O is like reading a book. File I/O follows a sequence events. The first step is to locate the file you want to use. The second step is to open the file. When you are done with the file, you close it.

File I/O operations such as reading or writing can be done only on an open file.

Three file types exist: sequential, random, and binary. Sequential access is the simplest file access, but is slow and cumbersome. Random access is a much faster and more useful method of access.

The programs that use random-access files are often more complex than sequential access programs.

Binary files are special, compacted forms of random-access files.