1. Any kind of constructors. 2. Function overloading. 3. Any types of Inheritance.
4. Search option.(any type of data)
5. Write and read data from text file.
For example, I have done numerous projects like bookshop management, Office salary management etc where name, id, price or salary etc different types of data have to be kept in a text file and also have to search those types of data from text file.