1. What is Scala?
a) A programming language
b) A database management system
c) A web application framework
Answer: a
2. What is the type hierarchy in Scala?
a) Any
b) AnyRef
c) AnyVal
d) All of the above
Answer: d
3. What is the difference between val and var in Scala?
a) val is immutable and var is mutable
b) var is immutable and val is mutable
c) Both are immutable
d) Both are mutable
Answer: a
4. What is a case class in Scala?
a) A class with a case statement
b) A class with pattern matching support
c) A class with both a case statement and pattern matching support
Answer: c
5. What is type inference in Scala?
a) The ability of the compiler to deduce the data type of a variable
b) The ability of the developer to specify the data type of a variable
c) Neither of the above
Answer: a
6. What is pattern matching in Scala?
a) A way of matching a value to a specific pattern
b) A way of joining two or more variables together
c) Neither of the above
Answer: a
7. What is a higher-order function in Scala?
a) A function that takes one or more functions as arguments
b) A function that returns another function
c) Both of the above
Answer: c
8. What is currying in Scala?
a) The process of converting a function with multiple arguments into a series of functions with only one argument
b) The process of removing a function from a given class or module
c) Neither of the above
Answer: a
9. What is lazy evaluation in Scala?
a) The process of delaying the evaluation of a computation until it is needed
b) The process of evaluating a computation as soon as it is defined
c) Neither of the above
Answer: a
10. What is an abstract class in Scala?
a) A class that cannot be instantiated
b) A class that can be instantiated
c) Neither of the above
Answer: a
11. What is a trait in Scala?
a) A construct that defines a set of methods and fields that can be mixed in with other classes
b) A type of inheritance
c) Neither of the above
Answer: a
12. What is a singleton object in Scala?
a) An object that is created once and is available throughout the application
b) A regular object that can be created multiple times
c) Neither of the above
Answer: a
13. What is a companion object in Scala?
a) An object that has the same name as a class and is defined in the same source file as the class
b) A regular object that can be created multiple times
c) Neither of the above
Answer: a
14. What is the difference between a final class and a sealed class in Scala?
a) A final class cannot be inherited and a sealed class can be inherited
b) A sealed class cannot be inherited outside the current source file and a final class can be inherited
c) Neither of the above
Answer: b
15. What is a future in Scala?
a) A construct that allows for asynchronous programming
b) A construct that allows for synchronous programming
c) Neither of the above
Answer: a
16. How can you declare multiple variables in Scala?
a) var a, b, c: Int
b) val a, b, c: Int
c) Both of the above
Answer: c
17. What is a higher-kinded type in Scala?
a) A type that takes a type constructor as an argument
b) A type that takes a value constructor as an argument
c) Neither of the above
Answer: a
18. What is an implicit in Scala?
a) A parameter that is automatically passed to a method
b) A method that is automatically called when a particular type is encountered
c) Neither of the above
Answer: b
19. What is the difference between a function and a method in Scala?
a) A function is a standalone object and a method is part of a class or object
b) A method is a standalone object and a function is part of a class or object
c) Neither of the above
Answer: a
20. What is a view in Scala?
a) A feature that allows for lazy evaluation of collections
b) A feature that allows for transformation of data types
c) Neither of the above
Answer: b
21. What is a partial function in Scala?
a) A function that is defined only for some values of its domain
b) A function that is defined only for all values of its domain
c) Neither of the above
Answer: a
22. What is a higher-order method in Scala?
a) A method that takes one or more functions as arguments
b) A method that returns another method
c) Both of the above
Answer: c
23. What is a map in Scala?
a) A collection that consists of key/value pairs
b) A collection that consists of only values
c) Neither of the above
Answer: a
24. What is an option in Scala?
a) A wrapper for a value that may or may not be present
b) A wrapper for a value that is always present
c) Neither of the above
Answer: a
25. What is a for comprehension in Scala?
a) A way of writing functional loops
b) A way of writing imperative loops
c) Neither of the above
Answer: a
26. What is tail recursion in Scala?
a) A recursive function that performs final calculations without making more recursive calls
b) A recursive function that makes more recursive calls
c) Neither of the above
Answer: a
27. What is a yield in Scala?
a) A keyword that is used to return the result of a loop as a collection
b) A keyword that is used to terminate a loop
c) Neither of the above
Answer: a
28. What is an implicit parameter in Scala?
a) A parameter that is automatically passed to a method
b) A method that is automatically called when a particular type is encountered
c) Neither of the above
Answer: a
29. What is a self-type annotation in Scala?
a) A way of restricting the type of objects that can mix in a trait
b) A way of specifying the type of a variable
c) Neither of the above
Answer: a
30. What is a type projection in Scala?
a) A way of accessing the type members of a class or trait
b) A way of creating a new type from an existing type
c) Neither of the above
Answer: a
31. What is a higher-rank type in Scala?
a) A type that takes a type constructor as an argument
b) A type that takes a value constructor as an argument
c) Neither of the above
Answer: a
32. What is an implicit conversion in Scala?
a) A function that converts one type to another
b) A method that is called when an unknown method is encountered
c) Neither of the above
Answer: a
33. What is a checked exception in Scala?
a) An exception that is checked at compile time
b) An exception that is checked at runtime
c) Neither of the above
Answer: a
34. What is a promise in Scala?
a) A construct that allows synchronous programming
b) A construct that allows asynchronous programming
c) Neither of the above
Answer: b
35. What is a manifest in Scala?
a) A way of providing access to the type parameters of a class or trait
b) A way of creating a new type from an existing type
c) Neither of the above
Answer: a
36. What is a context bound in Scala?
a) A way of providing implicit parameters to a method
b) A way of restricting the types that can be used as implicit parameters
c) Neither of the above
Answer: b
37. What is a value class in Scala?
a) A class that wraps a value and has no runtime overhead
b) A class that wraps a value and has runtime overhead
c) Neither of the above
Answer: a
38. What is a class tag in Scala?
a) A way of providing access to the type parameters of a class or trait
b) A way of creating a new type from an existing type
c) A way of providing runtime type information of a generic type
Answer: c
39. What is a context parameter in Scala?
a) A parameter that is automatically passed to a method
b) A method that is automatically called when a particular type is encountered
c) Neither of the above
Answer: a
40. What is an extractor in Scala?
a) A construct that allows for pattern matching on objects
b) A construct that allows for pattern matching on values
c) Neither of the above
Answer: a
41. What is a stackable trait in Scala?
a) A trait that can be mixed in with other traits
b) A trait that can be mixed in with classes
c) Neither of the above
Answer: a
42. What is type variance in Scala?
a) The relationship between two parameterized types
b) The relationship between two regular types
c) Neither of the above
Answer: a
43. What is an apply method in Scala?
a) A method that is called when an object is created
b) A method that is called when an object is used in a method call
c) Both of the above
Answer: a
44. What is a def macro in Scala?
a) A way of generating code during compilation
b) A way of generating code during runtime
c) Neither of the above
Answer: a
45. What is a typeclass in Scala?
a) A trait that defines a set of operations that can be performed on a type
b) A trait that defines a set of types that can be used in a method
c) Neither of the above
Answer: a
46. What is a lazy val in Scala?
a) A value that is only evaluated when it is needed
b) A value that is always evaluated
c) Neither of the above
Answer: a
47. What is an annotation in Scala?
a) A way of providing metadata about code to the compiler
b) A way of creating a new class or trait
c) Neither of the above
Answer: a
48. What is a duck typing in Scala?
a) A way of checking if an object has a specific method or property
b) A way of dynamically changing the type of an object
c) Neither of the above
Answer: a
49. What is a path-dependent type in Scala?
a) A type that depends on the path to the object that defines it
b) A type that depends on the type of an object that defines it
c) Neither of the above
Answer: a
50. What is a stackable modification in Scala?
a) A way of modifying the behavior of a method by mixing in traits
b) A way of modifying the behavior of a class by mixing in traits
c) Neither of the above
Answer: a
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