Kotlin Kotlin Extensions and Delegates 2

Question 1

What is property delegation in Kotlin?

Accepted Answer

Delegating the implementation of a property's get/set to another object

Answer

Passing a property to a function

Answer

Creating a copy of a property

Answer

Making a property abstract

Question 2

What does `Delegates.notNull()` do in Kotlin?

Accepted Answer

Ensures a property is initialized before access, throwing if accessed before assignment

Answer

Marks a property as non-nullable

Answer

Creates a property with a default value

Answer

Delegates to a companion object

Question 3

What is `lateinit` used for in Kotlin?

Accepted Answer

Allowing non-nullable var properties to be initialized after declaration without using null

Answer

Lazy initialization of nullable properties

Answer

Declaring properties in interfaces

Answer

Marking properties as thread-safe

Question 4

What is the difference between `lazy` and `lateinit` in Kotlin?

Accepted Answer

`lazy` is for val properties with computed initialization; `lateinit` is for var properties initialized externally

Answer

No difference

Answer

`lazy` supports primitives; `lateinit` does not

Answer

`lateinit` is thread-safe; `lazy` is not

Question 5

Which scope function is best for configuring a newly created object?

Accepted Answer

apply

Answer

let

Answer

run

Answer

also

Question 6

What is a `vetoable` delegate in Kotlin?

Accepted Answer

A delegate that lets you veto (reject) a new value before it is set

Answer

A delegate that makes a property read-only after first assignment

Answer

A delegate that logs property changes

Answer

A delegate that synchronizes access