Kotlin Kotlin OOP 3

Question 1

What is the difference between `interface` and `abstract class` in Kotlin?

Accepted Answer

Interfaces can have default implementations; abstract classes can have state and constructors

Answer

Kotlin interfaces can have default method implementations but cannot store state (no backing fields), whereas abstract classes can have constructors and maintain state.

Question 2

What does the `inner` keyword do when applied to a class in Kotlin?

Accepted Answer

Allows the nested class to access members of the outer class

Answer

An `inner` class in Kotlin holds a reference to its outer class and can access its members, unlike a regular nested class.

Question 3

What is an enum class in Kotlin?

Accepted Answer

A class that represents a fixed set of constants

Answer

An `enum class` in Kotlin defines a type with a fixed set of named constants, and each constant is an instance of the enum class.

Question 4

Which modifier makes a class member accessible only within the same file in Kotlin?

Accepted Answer

private

Answer

In Kotlin, `private` at the top level restricts visibility to the file in which it is declared.

Question 5

What is operator overloading in Kotlin?

Accepted Answer

Providing custom implementations for predefined operators using the `operator` keyword

Answer

Kotlin allows operator overloading by defining functions with specific names prefixed with the `operator` keyword, like `plus` for `+`.

Kotlin Practice Test

Kotlin Practice Test

Kotlin Kotlin OOP 3