File Processing

Files and Streams
• Similar to the standard input and output stream objects, file processing in C++ is accomplished by defining input and output file objects
• All file objects belong to one of thefollowing classes:
  • ifstream: Objects belonging to this class are associated with files opened for input purposes
  • ofstream: Objects belonging to this class are associated with files opened for output purposes
  • fstream: Objects belonging to this class are associated with files opened for input and output purposes
• These classes are defined in the header file fstream.h
• Data files are "attached" or "associated" with file objects using the open(char* ) member function of the file object
  

  #include <fstream.h>
  ifstream fin; // Define input file object
  fin.open("foo.txt") // Attach foo.txt to fin
  

• Files may also be attached by passing the file name to the file object's constructor:
  

  #include <fstream.h>
  ifstream fin("foo.txt") // Define fin and attach foo.txt to fin
  

• The insertor (<<) and extractor (>>) operators may be used to insert and extract data from the input and output file streams, respectively
• More Syntax...
• Examples of file processing...