Java OOPS Interview Questions

Here are some common Object-Oriented Programming (OOP) concepts questions you might encounter in a Java interview:

1. What is inheritance in Java and what is its purpose?
2. What is polymorphism and how does it work in Java?
3. What is encapsulation and why is it important in Java?
4. Can you explain the difference between method overloading and method overriding in Java?
5. What is the use of the “this” keyword in Java?
6. Can you explain the difference between an abstract class and an interface in Java?
7. What is a constructor in Java and what is its purpose?
8. What is a final class and a final method in Java?
9. What is the difference between a private and a protected method in Java?
10. Can you explain the concept of inheritance hierarchy in Java?
11. What is a package in Java and why is it useful?
12. What is a static method and a static variable in Java?
13. What is the difference between instance and class variables in Java?
14. Can you explain the concept of constructor chaining in Java?
15. What is the difference between a shallow and a deep copy in Java?
16. Can you explain the use of the “super” keyword in Java?
17. What is a nested class in Java and why is it used?
18. What is the difference between a checked and an unchecked exception in Java?
19. Can you explain the concept of inheritance with an example in Java?
20. What is the purpose of the “finalize” method in Java?
21. Can you explain the use of the “interface” keyword in Java?
22. What is the difference between a static and a non-static inner class in Java?
23. Can you explain the concept of polymorphism with an example in Java?
24. What is the use of the “synchronized” keyword in Java?
25. Can you explain the difference between a composition and an aggregation relationship in Java?
26. Can you explain the difference between inheritance and composition in Java?
27. What is the difference between a transient and a volatile variable in Java?
28. Can you explain the use of the “transient” keyword in Java?
29. What is the difference between a static and a dynamic binding in Java?
30. Can you explain the use of the “clone” method in Java?
31. What is the difference between a constructor and a factory method in Java?
32. Can you explain the difference between the “extends” and “implements” keywords in Java?
33. What is the difference between a HashMap and a Hashtable in Java?
34. Can you explain the concept of design patterns in Java and give an example of a design pattern?
35. What is the difference between a synchronized block and a synchronized method in Java?