Kotlin Quiz

1. Which keyword declares a read-only variable in Kotlin?

2. What does println() do?

3. Who created Kotlin?

4. What is the entry point of a Kotlin program?

5. Which of these is NOT a valid Kotlin data type?

6. What does the ? after a type mean in Kotlin?

7. What does the Elvis operator ?: do?

8. What does name?.length return when name is null?

9. What does 1..5 create in Kotlin?

10. Which Kotlin construct replaces switch from Java?

11. What is a default argument in Kotlin?

12. What does tailrec do in Kotlin?

13. What does listOf() return?

14. What does filter {} do on a collection?

15. What does a data class auto-generate?

16. What keyword makes a Kotlin class inheritable?

17. What is a sealed class in Kotlin?

18. What does it refer to in a Kotlin lambda?

19. What does delay() do in a Kotlin coroutine?

20. What is the difference between launch and async?

21. What is a cold Flow in Kotlin?

22. What does reified mean in a Kotlin inline function?

23. What symbol is used for string templates in Kotlin?

24. What is a companion object in Kotlin?

25. What does !! do in Kotlin?

26. Which is the correct way to declare a mutable variable?

27. What does the .. operator create?

28. How do you embed a variable in a string?

29. What does break do inside a for loop?

30. What does continue do in a loop?

31. What is a single-expression function?

32. What does the inline keyword do on a function?

33. What does map {} do on a list?

34. What does setOf() create?

35. How do you get a value from a map by key?

36. What is an object declaration in Kotlin?

37. What does override mean on a function?

38. What is an interface in Kotlin?

39. What is the type of { x: Int -> x * 2 }?

40. What does apply return?

41. What does with do?

42. Does Kotlin have checked exceptions like Java?

43. What does finally do in try/catch?

44. What is type erasure?

45. What is a coroutine scope?

46. What does await() do on a Deferred?

47. What is StateFlow used for?

48. Which file extension is used for Kotlin source?

49. What is a primary constructor in Kotlin?

50. What is a trailing lambda?

51. Which dispatcher should you use for disk or network I/O?

52. What does coroutineScope guarantee?

53. When should you use SharedFlow instead of StateFlow?

54. How do you access a companion object constant?

55. What does enum class create?

56. What is a top-level object declaration?