Library Management System

This project implements a Library Management System using Object-Oriented Programming (OOP) in C++. The system includes a Library class and a User class hierarchy with Student and Teacher as derived classes.

Features

• Add books in the library.
• Register and remove users (students and teachers).
• Borrow and return books.
• Display user information and book details.
• Display borrowed books.

Class Structure

1. Library Class

The Library class manages the collection of books and handles the lending process.

Members

• vector<Book*> availableBooks: A collection of books in the library.
• vector<User*> registeredUsers: A collection of users in the library.
• map<string, vector<pair<string, string> > > issuedBooks: A map of user IDs to books which user borrowed along with it's issued date.

Methods

• void addBook(book_name, author_name, isbn, quantity): Adds a new book to the library.
• void addUser(user_id, user_name, user_type): Registers a new user.
• void removeUser(user_id, remove_date): Remove user entry from library.
• void issueBook(userID, bookID): Lends a book to a user.
• void returnBook(userID, bookID): Returns a borrowed book.
• void listAvailableBooks(): Displays all available books in the library.
• void listRegisteredUsers(): Displays all registered users.
• void listIssuedBooks(): Displays all borrowed books along with user name who borrowed it and issued date.
• User* findUserById(userId) : Find user by it's ID.
• Book* findBookByIsbn(isbn) : Find book by it's ISBN;

2. Book Class

The Book class represents a book in the library.

Members

• string title: Title of the book.
• string authorName: The name of the book's author..
• string isbn: ISBN number of the book.
• int quantity: Available quantity of the book in the library.

Methods

• string getTitle(): Retrieves the title of the book.
• string getAuthorName(): Retrieves the author's name of the book.
• string getIsbn(): Retrieves the ISBN number of the book.
• int getQuantity(): Retrieves the available quantity of the book.
• void setQuantity(int quantity): Set the quantity of the book.

3. User Class

The User class is the base class for all users of the library.

Members

• string userId: The unique ID of the user.
• string userName: The name of the user.

Methods

• virtual double calculateFine(): Calculates the fine for overdue days. This method is virtual to support polymorphism.
• string getUserId(): Retrieves the user ID.
• string getUserName(): Retrieves the user name.

4. Student Class

The Student class is derived from the User class, representing student users.

Methods

• double calculateFine(): Calculate $1/day fine for overdue days.

5. Teacher Class

The Teacher class is derived from the User class, representing teacher users.

Methods

• double calculateFine(): Calculate $0.5/day fine for overdue days.

Application of OOP Principles

1. Encapsulation:

   • Definition: Encapsulation is wrapping up of data and member functions in a single unit called class.
   • Example: The Book class encapsulate attributes like title, authorName, and methods like getTitle() and getAuthorName.

2. Abstraction:

   • Definition: Hiding the complex implementation details and showing only the necessary parts to the user.
   • Example: The Library class provides an abstraction where users can perform actions like issued books and returning books without needing to know the internal details of how these operations are managed.

3. Inheritance:

   • Definition: Mechanism where a new class (derived class) is derived from an existing class (base class), inheriting its attributes and methods.
   • Example: The Student and Teacher classes inherit from the User class, gaining access to method calculateFine().

4. Polymorphism:

   • Definition: Ability of object to take on different forms or behave in different ways depending on the context in which they are used.
   • Example: Achieved through function overriding in derived classes. For instance, both Student and Teacher classes override a virtual method calculateFine() defined in the User base class. Each derived class can provide its own implementation to calculate different fine for student and teacher.

Future Enhancements

In the future, we plan to enhance the system with:

• Database Integration: Integrate a relational database (e.g., PostgreSQL, MySQL) to store and manage library resources, user data. This integration will ensure data persistence, efficient data retrieval, and scalability as the library grows.