This repository will be the Advanced and most complete for Object Oriented Programming. The repository will serve both beginners and advanced learners to understand advanced concepts of OOP. The programming language for this is still JAVA as my previous Basic OOP concepts repository covers the basics. In this Advanced OOP repository, I'll cover all four pillars Encapsulation, Abstraction, Inheritance, and Polymorphism. With Swing User Interface (checkboxes, buttons, Combobox, fields, textarea, Listbox, jtable, radiobuttons, etc.), Exceptions Handling, Throw Exceptions, Abstract Classes and methods, Method overloading and overriding, Math class, constructors, instances, Java Database Connectivity by Using PreparedStatement and way much more!