Kotlin MCQs (Chapterwise Multiple Choice Questions)

You have written a function, sort(), that should accept only collections that implement the Comparable interface. How can you restrict the function? fun sort(list: List): List { return list.sorted()}

Add Comparable> between the fun keyword and the function name

Add Comparable between the fun keyword and the function name

Add > between the fun keyword and the function name

Answer & Explanation

Correct Answer: Add > between the fun keyword and the function name

Note: This Question is unanswered, help us to find answer for this one

In this code snippet, why does the compiler not allow the value of y to change? For(y in 1..100) y+=2

Y must be declared with var to be mutable

Y is an implicitly immutable value

Y can change only in a while loop

In order to change y, it must be declared outside of the loop

Answer & Explanation

Correct Answer: Y is an implicitly immutable value

Note: This Question is unanswered, help us to find answer for this one

Which is the proper way to declare a singleton named DatabaseManager?

Object DatabaseManager {}

Singleton DatabaseManager {}

Static class DatabaseManager {}

Data class DatabaseManager {}

Answer & Explanation

Correct Answer: Object DatabaseManager {}

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Which line of code is a shorter, more idiomatic version of the displayed snippet? val len: Int = if (x != null) x.length else -1

Val len = x?.let{x.len} else {-1}

Val len = x!!.length ?: -1

Val len:Int = (x != null)? x.length : -1

Val len = x?.length ?: -1

Answer & Explanation

Correct Answer: Val len = x?.length ?: -1

Note: This Question is unanswered, help us to find answer for this one

What are the two ways to make a coroutine's computation code cancellable?

Call the yield() function or check the isActive property.

Call the cancelled() function or check the isActive property.

Call the stillActive() function or check the isCancelled property.

Call the checkCancelled() function or check the isCancelled property.

Answer & Explanation

Correct Answer: Call the yield() function or check the isActive property.

Note: This Question is unanswered, help us to find answer for this one

All classes in Kotlin inherit from which superclass?

Default

Super

Any

Object

Answer & Explanation

Correct Answer: Any

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What three methods does this class have? Class Person

Equals(), hashCode(), and toString()

Equals(), toHash(), and super()

Print(), println(), and toString()

Clone(), equals(), and super()

Answer & Explanation

Correct Answer: Equals(), hashCode(), and toString()

Note: This Question is unanswered, help us to find answer for this one

Which snippet correctly shows setting the variable max to whichever variable holds the greatest value, a or b, using idiomatic Kotlin?

Val max3 = a.max(b) (Extension Function is One of the idiomatic Solutions in Kotlin)

Val max = a > b ? a : b

Val max = if (a > b) a else b

If (a > b) max = a else max = b

Answer & Explanation

Correct Answer: Val max3 = a.max(b) (Extension Function is One of the idiomatic Solutions in Kotlin)

Note: This Question is unanswered, help us to find answer for this one

What is the default visibility modifier in Kotlin?

Protected

Private

Internal

Public

Answer & Explanation

Correct Answer: Public

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You are writing a console app in Kotlin that processes test entered by the user. If the user enters an empty string, the program exits. Which kind of loop would work best for this app? Keep in mind that the loop is entered at least once

A do..while loop

A for loop

A while loop

A forEach loop

Answer & Explanation

Correct Answer: A do..while loop

Note: This Question is unanswered, help us to find answer for this one

Kotlin Quick Quiz

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Start Practicing with our MCQs given below.