Clojure MCQ Questions Answers

1. A Clojure sequence is a Java

2. What is the Closure equivalent to ClassName.class in Java?

3. How many ways can you safely share mutable data using Clojure?

4. What's the value returned by... (let [[x y [z]] [2 4 [8 9]]] (list x y z))

5. (letfn [ (t [] (true? (some true? ["false"])))] (t))

6. The Clojure reader can be extended using _____

7. Refs _____

8. The application of advice or other aspect transformations is often called __________.

9. A _______ is a construct that suspends some body of code, evaluating it upon demand, when it is "deref"erenced.

10. If you want to create class that extends another class, you must use _____

11. What provides synchronous changes to a single, thread-local value?

12. Atoms _____

13. (.split "Java String" " ") returns

14. Agents _____

15. What does the "contains?" function work on?

16. Clojure is hosted on the JVM (Java Virtual Machine) and can use any Java library.

17. Which statement best describes protocols in Clojure?

18. Which of the following code fragments evaluates to 5?

19. True or False? Sets are collections of unique items. They are better than lists and vectors when duplicates aren't allowed.

20. Clojure documentation can be accessed

21. In Clojure, you can create a new class using _____

22. Which is a type of collection in Clojure?

23. What does the REPL tool do?

24. Clojure strings are Java Strings and are represented in exactly the same way, delimited by double quotes.

25. Which of the following Clojure fragments calculates (4+2)*(5-3)?

26. A function can be stored in a var or passed as an argument to other functions.

27. True or False? Arity is the number of arguments a function can handle.

28. What is the syntax of the "if" function?

29. True or False? In Clojure a symbol can contain characters that most imperative languages don't allow in variable names. (Example: in Clojure you can have a symbol with the name +a-.)

30. True or False? Clojure a functional language.

31. True or False? The Clojure language is homoiconic.

32. Does Clojure have a metadata system that allows for annotation of symbols and collections?

33. Leiningen uses _____ to locate and manage project dependencies

34. What is the function that evaluates a single argument form?

35. Which is an example of a Clojure function call?

36. What type does the following code result in? {:a 1 "b" 2}

37. How do you create an anonymous function?

38. Collections that classically support last-in, first-out (LIFO) semantics are called ____________.

39. True or False? Clojure programs only support some Java classes and interfaces.

40. What is significant about function names that end with a "!"?

41. The two comment types that are defined by the reader are:

42. How do you add metadata to a symbol or collection?

43. What do keywords begin with?

44. lib-noir, Ring, and Compojure are all examples of Clojure:

45. To calculate the average of some numbers in Clojure, your code would look like this:

46. What are sequences?

47. The map function is used to _____

48. Which statement about Clojure macros is true?

49. Stack abstraction is supported in Clojure via what three operations?

50. A built-in Clojure "operation" may be implemented as a...

51. :foo is an example of a(n) _____

52. REPL stands for _____

53. If you are already using Java or another JVM language for RDBMS work, it’s likely that you’re using ______________, easily the most popular Java object/ relational mapping library.

54. What type does the following code result in? [1 2 3 4]

55. What are the 3 phases Clojure code is processed in?

56. The reduce function is used to _____

57. STM stands for _____

58. True or False? A lazy-sequence can hold all the possible calculations of the Fibonacci sequence.

59. True or False? Metadata is data about data, and has no effect on the 'host' data.

60. Clojure provides several "persistent" data structures. Objects of these classes are _____

61. The following code will evaluate to true? (defn +++ [n] (+ (inc n) 1)) (= (+++ 1) 3)

62. How would you want to create a new Atom with an initial value <value>?

63. Clojure is primarily an imperative language.

64. What is generally the first step in deploying your Clojure web application?

65. ________ evaluates all of the expressions provided to it in order and yields the last expression's value as its value.

66. A(n) ________ is a named Emacs object that represents something editable, usually a file in your filesystem, but also the Clojure REPL or debugger, for example.

67. A multimethod is created using a ________form, and implementations of a multimethod are provided by ___________ form.

68. True or False? Clojure is NOT an imperative language.

69. What is the literal syntax for maps?

70. In many object-oriented languages, ________________ is a way to decouple a class from other objects upon which that class depends.

71. What is the conventional first and last character used to name vars intended to be bound to new, thread-local values?

72. ________ is a very low-level looping and recursion operation that is usually not necessary.

73. You can use ___________ whenever you like if you need a unique symbol, but its primary role is in helping us write hygienic macros.

74. (= (map + '(1 2 3)) 3)

75. True or False? Function definitions must appear before they're first used.

76. Which statement about -> and comp is true?

77. What's a difference between quote (') and syntax-quote (`) macro characters?

78. In Clojure, tail-call optimization is _____

79. To represent a boxed decimal in Clojure, you would use ____________.

80. Locks _____

81. Vars _____

82. True or False? (reset!) is used to set the value of an atom.

83. Which statement regarding Clojure "forms" is true?

84. For the following code to evaluate without error, what needs to be added? (def regex "<a>(.*)</a>") (re-seq regex "<a>Ryan Kelker</a>")