Four Pillars of OOP

Question: Explain the four pillars of Object-Oriented Programming with real-life examples.

Answer outline: Encapsulation — bundling data and the methods that operate on it, restricting direct access via access modifiers (e.g. a BankAccount class exposing deposit()/withdraw() but hiding the raw balance field). Abstraction — exposing only essential behavior while hiding implementation detail (e.g. a car's steering wheel/pedals abstract away the engine internals). Inheritance — a class acquiring properties/behavior from a parent class (e.g. Car and Truck inheriting from Vehicle). Polymorphism — the same interface behaving differently depending on the underlying object, via overriding (runtime) or overloading (compile-time).