Kotlin Questions

Pramesh Singh

Score: 🔥 32

Beginner

Took 2 months

Programming Language

Kotlin

86%

Questions Attempted

15 / 15

Correct Answers

Incorrect Answers

Points Earned

🔥 13

Question 1

How do you use a named argument when calling a function in Kotlin?

By simply passing the values in the correct order.
By using the '->' symbol followed by the argument name and value.
By specifying the argument name followed by '=' and the value inside the function call.
Named arguments are not supported in Kotlin.

Explanation:

Named arguments improve code readability by explicitly associating arguments with their corresponding parameters.

Question 2

What is the output of the following Kotlin code snippet?

val x = 5
if (x > 10) {
    println("Greater than 10")
} else if (x < 10) {
    println("Less than 10")
} else {
    println("Equal to 10")
}

Greater than 10
Less than 10
Equal to 10
The code will not compile

Explanation:

The code checks if the value of 'x' is greater than, less than, or equal to 10. Since 'x' is 5, which is less than 10, the code will print 'Less than 10'.

Question 3

What is the default visibility modifier for classes and members in Kotlin?

private
protected
internal
public

Explanation:

Unless specified otherwise, classes and members in Kotlin are accessible from anywhere, making 'public' the default visibility.

Question 4

How do you access the element at index 2 in a Kotlin array named 'numbers'?

numbers.get(2)
numbers[2]
numbers.indexOf(2)
numbers.elementAt(2)

Explanation:

Kotlin uses square brackets [] for array indexing, similar to many other programming languages.

Question 5

What is the output of the following code?

for (i in 1..5) {
    if (i == 3) continue
    println(i)
}

12345
1245
1234
124

Explanation:

The 'continue' keyword skips the current iteration when 'i' is 3, so 3 is not printed in the output.

Question 6

Which data type represents a whole number in Kotlin?

String
Float
Int
Boolean

Explanation:

The 'Int' data type is used to represent whole numbers in Kotlin, similar to 'int' in Java.

Question 7

What is the correct syntax to declare a class named 'MyClass' in Kotlin?

class MyClass()
class MyClass {}
public class MyClass
object MyClass

Explanation:

In Kotlin, 'class' keyword is used to declare a class. Curly braces '{}' are used to define the class body.

Question 8

What is the purpose of single-line comments in Kotlin?

To define code blocks
To declare variables
To add explanations or disable code temporarily
To import external libraries

Explanation:

Comments, marked by '//' in Kotlin, help explain code to yourself and others, or to temporarily disable parts of code without deleting them.

Question 9

What is the difference between 'val' and 'var' when declaring a property in Kotlin?

'val' declares a mutable property, 'var' an immutable one.
'val' declares an immutable property, 'var' a mutable one.
'val' is for local variables, 'var' for class properties.
There is no difference; they are interchangeable.

Explanation:

Properties declared with 'val' cannot be reassigned after initialization (similar to 'final' in Java), while 'var' properties can be changed.

Question 10

What is the size of the array declared in this Kotlin code?

val fruits = arrayOf("apple", "banana")

Explanation:

The code initializes an array named fruits with two elements: "apple" and "banana". Therefore, the size of the array is 2.

Question 11

What is the primary difference between listOf() and mutableListOf() in Kotlin?

listOf() creates an immutable list, while mutableListOf() creates a mutable list.
listOf() creates a list of integers, while mutableListOf() creates a list of strings.
listOf() creates a fixed-size list, while mutableListOf() creates a dynamically sized list.
There is no difference; both functions are interchangeable.

Explanation:

The core distinction lies in mutability. listOf() generates a read-only list, while mutableListOf() allows modifications like adding or removing elements after creation.

Question 12

What is the output of listOf(1, 2, 2, 3).toSet() in Kotlin?

[1, 2, 2, 3]
[1, 2, 3]
{1, 2, 2, 3}
{1, 2, 3}

Explanation:

toSet() converts the list to a Set, which removes duplicate elements. Sets are represented with curly braces {}.

Question 13

Which keyword is used to declare a class in Kotlin?

class
object
struct
interface

Explanation:

The 'class' keyword is used to define a blueprint for creating objects, which can hold data and functions.

Question 14

What is the primary constructor in Kotlin?

A constructor declared inside the class body.
A constructor declared using the 'constructor' keyword.
The constructor defined within the class header.
Kotlin doesn't have constructors.

Explanation:

In Kotlin, the primary constructor is declared directly in the class header, alongside the class name and any parameters it takes.

Question 15

How do you access the value associated with the key "name" in a Kotlin map named user?

user["name"]
user.name
user.get("name")
user.getValue("name")

Explanation:

In Kotlin, you can access the value associated with a key in a map using square brackets [] with the key inside.