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Kotlin interview questions

Kotlin interview questions.

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1.

What is a data class in Kotlin?

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2.

How to initialize an array in Kotlin with values?

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3.

What is the idiomatic way to remove duplicate strings from array?

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4.

Where should I use var and where val?

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5.

What is basic difference between fold and reduce in Kotlin? When to use which?

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6.

What is a primary constructor in Kotlin?

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7.

How to correctly concatenate a String in Kotlin?

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8.

What is the difference between var and val in Kotlin?

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9.

How to create singleton in Kotlin?

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10.

What is the difference between suspending vs. blocking?

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11.

val mutableList vs var immutableList. When to use which in Kotlin?

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12.

What is Lateinit in Kotlin and when would you use it?

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13.

How are extensions resolved in Kotlin and what doest it mean?

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14.

May you briefly compare Kotlin vs Java?

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15.

What is the difference between const and val?

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16.

What are some disadvantages of Kotlin?

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17.

Why would you use apply in Kotlin?

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18.

Explain the Null safety in Kotlin

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19.

What is the idiomatic way to deal with nullable values, referencing or converting them?

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20.

What is the equivalent of Java static methods in Kotlin?

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21.

Explain advantages of when vs switch in Kotlin

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22.

May you use IntArray and an Array is in Kotlin interchangeably?

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23.

What is suspending function in Kotlin?

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24.

How would you create a singleton with parameter in Kotlin?

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25.

When would you use Elvis operator in Kotlin?

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26.

What is the Kotlin double-bang (!!) operator?

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27.

What are scope functions in Kotlin?

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28.

What are coroutines in Kotlin?

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29.

What are the advantages of Kotlin over Java?

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30.

What is a difference between a class and object in Kotlin?

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31.

What is the purpose of Unit-returning in functions? Why is VALUE there? What is this VALUE?

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32.

When to use lateinit over lazy initialization in Kotlin?

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33.

Explain lazy initialization in Kotlin

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34.

What is the difference between List and Array types?

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35.

What is a purpose of Companion Objects in Kotlin?

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36.

How is it recommended to create constants in Kotlin?

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37.

What is the difference between open and public in Kotlin?

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38.

Explain what is wrong with that code?

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39.

How would you refactor this code using apply?

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40.

How to convert List to Map in Kotlin?

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41.

What will be result of the following code execution?

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42.

Rewrite this code in Kotlin

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43.

How can I create static method for enum in Kotiln?

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44.

What is Kotlin backing field is used for?

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45.

Explain the difference between Inline classes vs type aliases

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46.

Why is there no static keyword in Kotlin?

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47.

What are Object expressions in Kotlin and when to use them?

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48.

What is Coroutine Scope and how is that different from Coroutine Context?

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49.

Provide a real use case when inline classes may be useful

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50.

What is the difference between launch/join and async/await in Kotlin coroutines?

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51.

What is The Billion Dollar Mistake?

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52.

How does the reified keyword in Kotlin work?

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53.

How Kotlin coroutines are better than RxKotlin/RxJava?

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54.

What is the difference between Java field and Kotlin property?

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55.

When to use and do not use an inline function in Kotlin?

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56.

What is a motivation to make classes final by default in Kotlin? Do you agree with that decision?

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57.

Why do we use “companion object” as a kind of replacement for Java static fields in Kotlin?

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58.

What is SAM Conversion in Kotlin?

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59.

What is the difference between * and Any in Kotlin generics?

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60.

Explain the difference between lateinit and lazy in details

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61.

What is inline class in Kotlin and when do we need one? Provide an example.

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62.

How to create an instance of anonymous class of abstract class in Kotlin?

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63.

How to create empty constructor for data class in Kotlin?

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64.

Rewrite this code using run extension function

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65.

How would you override default getter for Kotlin data class?

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66.

What's wrong with that code?

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67.

How to implement Builder pattern in Kotlin?

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68.

Imagine you moving your code from Java to Kotlin. How would you rewrite this code in Kotlin?

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7 Layering & Middleware interview questions for developers

Middleware in the context of distributed applications is software that provides services beyond those provided by the operating system to enable the various components of a distributed system to communicate and manage data. Middleware supports and simplifies complex distributed application...

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55 Docker interview questions and answers for software engineers

Docker is a set of platform as a service products that use OS-level virtualization to deliver software in packages called containers. Here is a list of coding interview questions on Docker to help you get ready for your next data structures interview in 2021.

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23 Databases interview questions and answers for software engineers

A database is an organized collection of data, generally stored and accessed electronically from a computer system. Where databases are more complex they are often developed using formal design and modeling techniques. Here is a list of coding interview questions on Databases to help you g...

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21 Concurrency interview questions and answers for software engineers

In computer science, concurrency is the ability of different parts or units of a program, algorithm, or problem to be executed out-of-order or in partial order, without affecting the final outcome. Here is a list of coding interview questions on Concurrency to help you get ready for your n...

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13 CAP Theorem interview questions and answers for software engineers

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