C++ Files

📁 C++ Files (File Handling)

File handling in C++ allows you to read from and write to files stored on disk.
It is commonly used for data storage, logs, reports, configuration files, etc.

C++ file handling is done using the <fstream> library.

🔹 1. Header Files for File Handling

Key classes:

• ifstream → input file stream (read)

• ofstream → output file stream (write)

• fstream → both read and write

🔹 2. Writing to a File (ofstream)

Example: Write Text to a File

✔ Creates file if it doesn’t exist
✔ Overwrites file if it exists

🔹 3. Reading from a File (ifstream)

Example: Read Entire File

🔹 4. Reading Word by Word

🔹 5. Using fstream (Read + Write)

🔹 6. File Open Modes

Example:

🔹 7. Append Data to a File

✔ Old data preserved

🔹 8. Check If File Opened Successfully

🔹 9. Write and Read Numbers

🔹 10. Binary File Handling

Write Binary File

Read Binary File

❌ Common Mistakes

✔ Correct:

🔁 File Handling vs Console I/O

📌 Summary

• File handling uses <fstream>

• ofstream → write

• ifstream → read

• fstream → read & write

• Always close() files

• Supports text and binary files