Lesson 5.1

• Writing to a File


  Write information to a file using the stream insertion operator (<<) with an ofstream or fstream object
• Header files <iostream> and <fstream> must be included in C++ source file for file processing
• fstream

  • Defines three new data types: ofstream, ifstream, fstream
  • ofstream: Represents the output file stream for creating and writing information to files
  • ifstream: Represents the input file stream for reading information from files
  • fstream: Represents the file stream generally, with capabilities of both ofstream and ifstream for creating files, writing information, and reading information
• close() function is used to close a file
• Standard syntax for open() function: void open(const char *filename, ios::openmode mode)
• Reading from a File

  Read information from a file using the stream extraction operator (>>) with an ifstream or fstream object
• Opening a File

  1. A file must be opened before reading from or writing to it

  2. Either ofstream or fstream object is used to open a file for writing

  3. ifstream object is used to open a file for reading