Core Java All Interview Questions in one place for android developers Part 7 of. N

I Have taken most of the questions from people’s interview reviews from glassdoor and combining them in one place.

  1. What are JRE, JDK, and JVM?
  2. Internal working of JVM? (Deep understanding of all the areas)
  3. Memory areas in JVM?
  4. JIT Compiler?
  5. What is the classloader in detail?
  6. Why main() method is required to run the java program?
  7. Explain the main() method in detail?
  8. Why main() method is static?
  9. What all combinations allowed in the declaration of the main() method?
  10. Can the main() method be final? and synchronize? can we add strictfp keyword?
  11. Can we run a java program without the main() method if yes then how?
  12. Explain System.out.println() ?
  13. What is the Garbage collection how it works explain in detail?
  14. Oops, concepts in detail?
  15. Is java a pure object-oriented programming language? (NO due to default support of primitive data type and static keyword)
  16. What is a constructor in detail(How to invoke type, Chaining, etc)
  17. What is a method in java?
  18. Difference between method and constructor?
  19. This and super keywords in java?
  20. Why we can't use this in a static context?
  21. All about static(method, class, block)?
  22. Explain IS-A and HAS-A relationship in detail? (Association, composition, strong ref, and weak ref)
  23. Abstraction in oops?
  24. Difference between Abstraction and Encapsulation?
  25. What is wrapper class?
  26. Boxing and Unboxing?
  27. Autoboxing and auto unboxing?
  28. What is Object class? methods of object class?
  29. What are magic methods (Methods of object class is called magic methods)?
  30. Hashcode() and equals() method?
  31. Inner classes in java?
  32. Enum in java?
  33. SIB and IIB in java?
  34. Final keyword in java?
  35. Access modifiers in java?
  36. What are wrapper classes?
  37. Call by value and call by reference?
  38. What is Interface, Marker interface Functional interface?
  39. StrictFp and volatile keywords?
  40. String, StringBuffer, and StringBuilder all the combination of questions?
  41. Create an immutable class?
  42. Multithreading in detail?
  43. Exception handling in detail?
  44. Final, Finally, Finalize?
  45. Overloading &Overriding?
  46. Method hiding?
  47. Collection framework in detail?
  48. Difference between collection and Collections?
  49. Map in detail?
  50. Internal working of hashmap?
  51. Comparable vs Comparator?
  52. Java new features?

Note: I have mentioned topics here please understand deeply the concepts of these topics, Interview questions will be from above only.

Will be adding more questions here.

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Senior Android App Developer | Startup | Product base | Java | Kotlin | MVVM | Architecture components | Android Blogger

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Aalishan Ansari

Aalishan Ansari

Senior Android App Developer | Startup | Product base | Java | Kotlin | MVVM | Architecture components | Android Blogger

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