Java Interview Questions

We have  n number of questions might ask regarding java. I mean each concept of  have lot of scope to discuss. Here i will give some of questions i have faced. Here we might need to write program also to explain any of the feature like runtime polymorphsim oo to iterate hashmap etc...

1. What are Object Oriented Principles?
Ans: Inheritance, Abstraction, Encapsulation and Polymorphism etc

2. What is abstraction?
Ans : Abstraction in Java

3.What is Interface?
Ans: Interface in Java 

4. What is polymorphism?
Ans: Polymorphism in Java

5. What is multi threading how we can implement in Java?
Ans: Multi Threading in Java

6. What is String pool?
Ans: String pool in java

7. Why String is immutable?
Ans :  Why String is immutable

8. What is this, final  ans super keywords?
Ans:  this      final     super

9. What is method overriding and method overloading?

Ans :  method overriding     and    method overloading

10. How to handle Exception in java?

Ans : Exceptions in Java

11. What is checked and unchecked exception?
Ans : Exception in Java

12. What are access modifiers in java?
Ans:  access modifiers in java

13. What is arraylist?
 Ans: ArrayList

14. Difference between list and set?
Ans: List Vs Set

15. What is comparator in java?

16. What is HashMap in java?
Ans: HashMap in Java

17. How HashMap will work 

18. What is Hashtable in Java?
Ans : HashTable in java

19. How to sort a collection?

20. What is String intern?
Ans : String intern in Java

21. Differences between String Buffer and String Builder?
 Ans: String Vs StringBuffer Vs StringBuilder