Kotlin Basic Quiz

Welcome to your Kotlin Basic Questions

Name

What does the following Kotlin program do?

fun main() {
 var n = 10
 var factorial = 1
 while (n > 0) {
 factorial *= n
 n--
 }
 println(factorial)
}

Prints the first 10 prime numbers.

Calculates the sum of the first 10 numbers.

Prints the numbers from 10 to 1 in reverse order.

Calculates the factorial of 10.

None

Given the following Kotlin program, what will be the value of max?

val num1 = 10
val num2 = 25
val num3 = 15
val max = if (num1 >= num2 && num1 >= num3) num1
else if (num2 >= num1 && num2 >= num3) num2
else num3

None

What is the range operator used to create a range of numbers in Kotlin?

None

What is the output of the following Kotlin program?

fun main() {
 var a = 5
 var b = 10
 a = b.also { b = a }
 println("After swapping: a = $a, b = $b")
}

After swapping: a = 5, b = 10

After swapping: a = 10, b = 5

After swapping: a = 0, b = 0

This program will not compile.

None

In Kotlin, which collection type represents an ordered list of elements?

Set

List

Map

Array

None

Which Kotlin feature helps prevent null pointer exceptions?

Unicorn operator (->>)

Elvis operator (?:)

Star operator (*)

Arrow operator (->)

None

In Kotlin, what is the purpose of the "fun" keyword?

It defines a new data type

It declares a function

It stands for "funny"

It specifies a variable's data type

None

How can you define a read-only property in Kotlin?

Using the "get" keyword

Using the "val" keyword

Using the "readonly" keyword

Using the "var" keyword

None

What is the output of the following Kotlin program?

fun main() { 
 var sum = 0
 for (i in 1..10) {
 sum += i
 } 
 println(sum) 
}

None

10.

How do you declare a nullable variable in Kotlin?

Using the ! operator

Using the ? operator

Using the # symbol

Using the * symbol

None

11.

Given the following Kotlin program, what will be the value of result?

val x = 5
val y = 3
val result = x * y

None

12.

What is the Kotlin equivalent of a "for loop" in other programming languages?

repeat loop

foreach loop

while loop

for-in loop

None

13.

In Kotlin, what keyword is used to declare a function?

fun

proc

method

func

None

14.

What is the output of the following Kotlin program?

fun main() {
 var fib1 = 0
 var fib2 = 1
 for (i in 1..10) {
 print("$fib1, ")
 val next = fib1 + fib2
 fib1 = fib2
 fib2 = next
 }
}

1, 1, 2, 3, 5, 8, 13, 21, 34, 55,

0, 1, 1, 2, 3, 5, 8, 13, 21, 34,

0, 1, 2, 3, 4, 5, 6, 7, 8, 9,

This program will not compile.

None

15.

What is the output of the following Kotlin program?

fun main() {
 val numbers = arrayOf(1, 2, 3, 4, 5)
 val sum = numbers.reduce { acc, num -> acc + num }
 println(sum)
}

120

None

1 out of 15