The Four Pillars of OOP with Your Own Examples
50 min · Beginner
The four pillars of OOP are encapsulation, inheritance, polymorphism and abstraction. Interviewers rarely want textbook lines: they want a one-line definition, a tiny Java example you wrote yourself, and a clear answer to the classic follow-ups.
Topics in this lesson
- One line and one example for each pillar
- Encapsulation vs abstraction: the classic confusion
- Compile-time vs runtime polymorphism
- Types of inheritance and the diamond problem
- Analogies interviewers accept and reject
Interview questions this lesson answers
- What is OOP?
- What are the four pillars of OOP?
- What is encapsulation?
- What is inheritance?
- What is polymorphism?
- What is abstraction?
- What is a class and what is an object?
- What is the difference between encapsulation and abstraction?
- Is data hiding the same as encapsulation?
- Are getters and setters enough for encapsulation?
Sign in free to continue this lesson
Create a free account to read every lesson, practise with the exercises and keep track of your progress.