Innovative Kotlin Test - 78+ MCQs: Kotlin test: Evaluate Your Programming Skills with Kotlin Questions and Answers

1. How does Kotlin handle default arguments in functions?

By using the 'default' keyword

By declaring functions with an empty body

By specifying default values for parameters

Kotlin does not support default arguments

2. What is the purpose of the 'sealed class' in Kotlin?

To restrict the inheritance of a class hierarchy

To declare a class with restricted access modifiers

To define a class with a limited number of instances

To create a class with private constructors

3. What is the purpose of the 'groupBy' function in Kotlin?

To create a new group of elements

To group elements based on a key selector

To handle program initialization

To define a scope for multiple function calls on the same object

4. How do you declare an extension property in Kotlin?

property String myProperty

String myProperty property

val String.myProperty

val myProperty: String

5. What is the purpose of the 'let' extension function in Kotlin?

To create a new variable

To apply a function to each element of a collection

To define a scope for the current object

To handle program initialization

6. How do you declare an interface in Kotlin?

interface MyInterface {}

MyInterface {}

class MyInterface {}

MyInterface : class {}

7. In Kotlin, what is the purpose of the 'also' function?

To apply a function to each element of a collection

To handle program initialization

To define a scope for the current object

To perform additional operations on an object and return it

8. In Kotlin, what is the purpose of the 'let' extension function?

To create an extension function for nullable types

To handle program initialization

To apply a function to the result of a nullable expression

To define a lambda expression

9. How do you declare a nullable variable in Kotlin?

var x: Int = null

var x: Int? = null

val x: Int? = 0

val x: Int = null

10. What is the syntax for a single-line comment in Kotlin?

// This is a comment

# This is a comment

/** This is a comment */

-- This is a comment

11. How do you define an extension function in Kotlin?

fun String.extendFunction() {}

String fun extendFunction() {}

extend fun String.extendFunction() {}

fun extendFunction() String {}

12. How does Kotlin handle primary constructors in a class?

By allowing only one primary constructor

By requiring explicit declaration and initialization

By allowing implicit declaration and initialization

Kotlin does not support primary constructors

13. What is the purpose of the 'tailrec' modifier in Kotlin?

To define a recursive function

To mark the last element of a collection

To specify the tail of a class

To optimize tail-recursive functions

14. Which keyword is used for type casting in Kotlin?

cast

convert

15. What is the purpose of the 'trim' function in Kotlin?

To trim leading and trailing whitespace

To resize a collection

To remove null values from a collection

To handle program termination

16. What is the purpose of 'lateinit' in Kotlin?

To specify a variable as constant

To indicate that a variable will be initialized later

To declare a variable with nullable type

To enforce immutability for a variable

17. In Kotlin, what is the purpose of the 'reified' keyword?

To declare a variable as reified

To create a recursive function

To specify a function as reified

Kotlin does not have a 'reified' keyword

18. What is the purpose of the 'sealed' modifier in Kotlin?

To indicate that a class can be inherited

To restrict the inheritance of a class to its subclasses within the same file

To declare a class as abstract

To create a sealed package

19. What is the purpose of the 'reduce' function in Kotlin?

To reduce the size of a collection

To combine elements of a collection into a single result

To apply a function to each element of a collection

To remove null values from a collection

20. What is the purpose of the 'forEach' function in Kotlin?

To iterate over a range of values

To perform a case-insensitive comparison

To iterate over elements of a collection

To apply a function to each element of a collection

21. What is the purpose of the 'crossinline' modifier in Kotlin?

To declare external declarations for platform-specific code

To create a cross-platform function

To mark a function as non-nullable

To prevent non-local returns in an inline function

22. How do you declare a package in Kotlin?

package com.example.myPackage

com.example.myPackage

declare package com.example.myPackage

package: com.example.myPackage

23. What is the purpose of the 'reified' keyword in Kotlin?

To enforce immutability for a variable

To specify a type parameter at runtime

To create a recursive function

To mark a class as reusable

24. How does Kotlin handle extension properties?

Kotlin does not support extension properties

By using the 'extension' keyword

By declaring them in a separate extension file

By using the 'property' keyword

25. How do you declare a generic class in Kotlin?

class MyClass<T> {}

generic class MyClass {}

class MyClass : generic {}

T class MyClass {}

26. How do you declare an enum class in Kotlin?

enum class MyEnum {}

class enum MyEnum {}

enum MyEnum : class {}

class MyEnum : enum {}

27. In Kotlin, what is the 'operator overloading' feature used for?

To overload the '+' operator for custom classes

To define the priority of operators

To mark a class as an operator

To handle program initialization

28. How does Kotlin handle null safety?

By allowing null values for all variables

By using the 'nullable' keyword

By introducing the 'null' type

By making nullable and non-nullable types explicit

29. What is the purpose of the 'by' keyword in Kotlin?

To indicate the inheritance hierarchy

To specify the visibility modifier

To delegate property behavior to another object

To create a bi-directional reference

30. What is the purpose of the 'by lazy' keyword in Kotlin?

To specify lazy loading for classes

To create a lazy property that is computed the first time it is accessed

To declare external declarations for platform-specific code

To define the priority of operators

31. What is the purpose of the 'invoke' function in Kotlin?

To create a new instance of a class

To call instances of a function type

To handle program termination

To invoke a secondary constructor

32. How do you define a class with a private constructor in Kotlin?

class MyClass { private constructor() }

class MyClass(private constructor()) {}

class MyClass private constructor() {}

class MyClass(private constructor) {}

33. What is the purpose of the 'expect' keyword in Kotlin?

To define expected behavior for a function

To specify the return type of a function

To declare external declarations for platform-specific code

To create conditional expressions

34. Which keyword is used to define a constant in Kotlin?

const

val

var

final

35. What is the purpose of the 'apply' function in Kotlin?

To apply mathematical operations

To apply functions to each element of a collection

To configure the properties of an object during its creation

To handle program initialization

36. What is the purpose of the 'with' function in Kotlin?

To create a new instance of a class

To apply a function to each element of a collection

To define a scope for multiple function calls on the same object

To handle program termination

37. In Kotlin, what is the purpose of the 'yield' function?

To yield control to another coroutine

To yield a value from a generator function

To yield the execution of a loop

Kotlin does not have a 'yield' function

38. What is the purpose of the 'noinline' modifier in Kotlin?

To prevent inlining of a function

To mark a function as non-nullable

To enforce immutability for a variable

To specify the return type of a function

39. How do you define a function in Kotlin?

function myFunction() {}

fun myFunction() {}

define myFunction() {}

fun: myFunction() {}

40. What is the purpose of the 'flatMap' function in Kotlin?

To apply a function to each element of a collection

To flatten a collection of collections

To create a new collection with transformed elements

To handle program initialization

41. In Kotlin, what is the purpose of the 'noinline' modifier for functions?

To indicate that a function should not be inlined

To define a function as non-recursive

To disable tail-call optimization

Kotlin does not have a 'noinline' modifier

42. How do you declare a generic function in Kotlin?

fun <T> myFunction() {}

generic fun myFunction() {}

fun myFunction<T>() {}

T fun myFunction() {}

43. In Kotlin, what is the 'invoke' operator used for?

To create an instance of a class

To define the behavior of calling an instance as a function

To specify the return type of a function

To declare external declarations for platform-specific code

44. How do you declare a function with an infix notation in Kotlin?

fun add(a: Int, b: Int) = a infixPlus b

fun add(a: Int, b: Int) = a + infix b

infix fun add(a: Int, b: Int) = a + b

fun infix add(a: Int, b: Int) = a + b

45. In Kotlin, how do you create a class with a primary constructor?

class MyClass { constructor() }

class MyClass : constructor() {}

class MyClass constructor() {}

class MyClass() {}

46. What is the syntax for a multiline string in Kotlin?

`This is a multiline string`

'This is a multiline string'

"This is a multiline string"

'''This is a multiline string'''

47. What is the purpose of the 'coroutine' keyword in Kotlin?

To create a coroutine function

To specify the return type of a coroutine

Kotlin does not have a 'coroutine' keyword

To handle program termination

48. What is the purpose of the 'first' function in Kotlin?

To specify the first element of a collection

To apply a function to the first element of a collection

To retrieve the first element that matches a predicate

To create a new collection with the first element

49. In Kotlin, what is the 'getter' keyword used for?

To specify the visibility modifier

To define the getter function for a property

To declare external declarations for platform-specific code

To create a lazy property

50. What is the purpose of the 'break' statement in Kotlin?

To end the program execution

To exit the current loop or when statement

To skip the next iteration of a loop

To return a value from a function

Kotlin MCQ Test 1