Mostly Asked Java Interview Questions CHEAT SHEET for Freshers 🚀

Core Java Questions

1. What is the difference between JDK, JRE, and JVM?
2. What are the main features of Java?
3. Explain the concept of Object-Oriented Programming (OOP) and its principles.
4. What are the access modifiers in Java, and what do they mean?
5. What is the difference between == and equals() method in Java?
6. What is the purpose of the final keyword in Java?
7. What are the differences between an abstract class and an interface?
8. What is a static keyword in Java, and where can it be used?
9. Explain the difference between checked and unchecked exceptions.
10. What is a Java package, and what are its advantages?

Advanced Java Concepts

11. What is multithreading, and how is it implemented in Java?
12. Explain the difference between String, StringBuilder, and StringBuffer.
13. What is garbage collection in Java, and how does it work?
14. What are Java Collections Framework? Give examples of its classes.
15. What is the difference between ArrayList and LinkedList?
16. What is the significance of the volatile keyword in multithreading?
17. What is the difference between HashMap and Hashtable?
18. Explain the concept of Java Memory Model (Heap and Stack).
19. What are the differences between Comparator and Comparable?
20. What are functional interfaces in Java, and how are they used in lambda expressions?