OOP Concepts Interview Questions

Four pillars, abstract class vs interface, SOLID, design patterns, LLD warmups, and tricky output questions.

30 questions in this section

Class vs Object (Beginner)
Four Pillars of OOP (Beginner)
Encapsulation and Data Hiding (Beginner)
Abstraction: Hiding Complexity (Beginner)
Inheritance and Its Types (Beginner)
Polymorphism: Compile-time vs Run-time (Beginner)
Constructors and Destructors (Beginner)
Method Overloading vs Overriding (Beginner)
Access Modifiers in Java and C++ (Beginner)
this and super Keywords (Beginner)
Static vs Dynamic Binding (Intermediate)
Abstract Class vs Interface (Intermediate)
static Keyword: Variables, Methods, Blocks (Intermediate)
Composition vs Inheritance (Intermediate)
The Diamond Problem (Intermediate)
Coupling and Cohesion (Intermediate)
SOLID: Single Responsibility and Open/Closed (Intermediate)
Liskov Substitution Principle (Intermediate)
SOLID: Interface Segregation and Dependency Inversion (Intermediate)
Singleton Pattern (Intermediate)
Factory Pattern (Intermediate)
Observer Pattern (Intermediate)
Strategy Pattern (Intermediate)
Builder Pattern (Advanced)
Tricky Output: Field Hiding and Overload Resolution (Advanced)
Tricky Output: Initialization Order (Advanced)
Immutable Classes and equals/hashCode Contract (Advanced)
Design a Parking Lot (LLD) (Advanced)
Design a Vending Machine or ATM (State Pattern) (Advanced)
Virtual Functions, vtable and Object Slicing in C++ (Advanced)

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