Java Fundamentals

⏷ 6. What is the difference between == and equals() in Java?

⏷ 7. What happens if you assign a long to an int? How would you handle such a situation in Java?

⏷ 8. What’s the difference between a checked and unchecked exception? Can you explain with examples of each?

⏷ 9. What is the difference between the Comparable and Comparator interfaces

⏷ 10. What Is a ClassLoader?

⏷ 11. What Is the purpose of the Serializable interface?

⏷ 12. What happens if there is no break in a switch statement?

⏷ 13. Why are Strings immutable in Java, and when would you prefer StringBuilder over String?

⏷ 14. Reverse a String without using any library method

⏷ 15. Validate an Email Address using Pattern and Matcher

⏷ 16. How would you read a file line by line in Java?

⏷ 17. What happens if there is a return statement in the try block and the finally block?

⏷ 18. What is the difference between Exception and Error in Java?

⏷ 19. Can you explain the hierarchy of exceptions in Java?

⏷ 20. What happens if an Exception is thrown in a static block?

⏷ 21. How do you create a Custom Exception in Java? When it’s useful?

⏷ 22. What are best practices for exception handling in Java?

⏷ 23. What is a NullPointerException, and how can you prevent it?

⏷ 24. How do you handle exceptions in a multi-threaded environment?

⏷ 25. What is the difference between ? extends and ? super in generics?

⏷ 26. How do you create a generic method in Java?

⏷ 27. Can you explain the purpose of the T, E, K, and V placeholders in generics?

⏷ 28. Write a program to create a generic class for a simple stack implementation.

⏷ 29. What is the Java memory model, and how is memory divided in the JVM?

⏷ 30. What is the difference between stack memory and heap memory?

⏷ 31. What is garbage collection in Java, and why is it important?

⏷ 32. What is a memory leak in Java, and how can it occur despite garbage collection?

⏷ 33. To avoid memory leaks why is best practice to avoid unnecessary static references.

⏷ 34. How can you use WeakHashMap for Automatic Cleanup?

⏷ 35. What are OutOfMemoryError and StackOverflowError, and how do you handle them?

⏷ 36. What is the purpose of the finalize() method, and why is it discouraged?

⏷ 37. What tools or techniques can you use to analyze and optimize memory usage in Java?

⏷ 38. What is the purpose of the @FunctionalInterface annotation?

⏷ 39. How do Predicate and Function differ in Java?

⏷ 40. How can you use method references to simplify code with lambda expressions?

⏷ 41. What is the purpose of the Optional class? Provide multiple examples.

⏷ 42. What are the main differences between Date and LocalDate in Java?

⏷ 43. How do you format a LocalDateTime object to a specific pattern?

⏷ 44. How do you calculate the difference between two dates in Java 8?

⏷ 45. How do you convert a legacy Date object to a LocalDate?

⏷ 46. What is Reflection? Give an example of functionality that can only be implemented using reflection.

⏷ 47. What are the different retention policies for annotations?

⏷ 48. How do you create a custom annotation in Java?

⏷ 49. What are the new String methods introduced in Java 11, and how do they differ from Java 8?

⏷ 50. What is the purpose of the var keyword introduced in Java 10, and is it available in Java 8?

⏷ 51. How does the new HTTP Client API in Java 11 improve over the HTTP libraries used in Java 8?

⏷ 52. What new features in sealed classes introduced in Java 17 make them different from regular inheritance models in Java 11?

⏷ 53. What are the improvements in pattern matching in Java 17 compared to Java 11?

⏷ 54. How does Java 17 improve text blocks compared to Java 11?

⏷ 55. What are records, and how do they differ from regular Java classes?