Introduction
In C++, file handling is essential for reading from and writing to files. This is accomplished using two primary classes: ifstream and ofstream.
ifstream (Input File Stream)
- Purpose: Used to read data from files.
- Functionality:
- Allows you to open a file in read mode.
- Data can be extracted using the extraction operator (>>).
- Common Methods:
- `open()`: Opens the specified file.
- `close()`: Closes the file.
- `getline()`: Reads a line from the file.
- Example Usage:
- To read integers from a file, you can use:
cpp
ifstream inputFile("data.txt");
int number;
inputFile >> number;
ofstream (Output File Stream)
- Purpose: Used to write data to files.
- Functionality:
- Allows you to open a file in write mode.
- Data can be inserted using the insertion operator (< />
- Common Methods:
- `open()`: Opens the file for writing.
- `close()`: Closes the file.
- `write()`: Writes binary data to the file.
- Example Usage:
- To write integers to a file, you can use:
cpp
ofstream outputFile("data.txt");
outputFile < />
Key Differences
- Input vs Output:
- ifstream is for input (reading), while ofstream is for output (writing).
- File Modes:
- ifstream uses modes like `ios::in`, whereas ofstream uses `ios::out`.
- Error Handling:
- Both classes provide methods to check if a file is opened successfully.
Conclusion
Understanding the distinctions between ifstream and ofstream is crucial for effective file manipulation in C++. Each serves its unique role in the file handling process, ensuring smooth data input and output operations.