The 10 Most Important Kotlin (Android) Interview Questions You Need To Know In 2023 (5 Easy, 3 Medium, 2 Hard)/

Kotlin is a modern programming language that runs on the Java Virtual Machine and can be used for a wide range of applications. Whether you’re new to Kotlin or an experienced developer, it’s essential to understand the language concepts, syntax, and best practices. In this blog post, we’ll provide you with 10 of the most important Kotlin interview questions.

5 Easy Kotlin Interview Questions

1. What is Kotlin programming language?
   Kotlin is a modern, statically typed programming language that runs on the Java Virtual Machine (JVM). It was designed to be concise, expressive, and interoperable with existing Java code.
2. What are the benefits of using Kotlin?
   Some of the benefits of using Kotlin include concise syntax, null safety, interoperability with Java, improved type inference, and support for functional programming.
3. What is a data class in Kotlin?
   A data class in Kotlin is a class that is designed to hold data. It automatically generates methods like equals(), hashCode(), and toString(), making it easier to work with data objects.
4. What is the difference between “val” and “var” in Kotlin?
   “val” is used to declare a read-only variable, while “var” is used to declare a mutable variable. Once a “val” variable is assigned, it cannot be changed, while a “var” variable can be changed throughout the execution of a program.
5. What are higher-order functions in Kotlin?
   Higher-order functions in Kotlin are functions that take other functions as parameters or return functions as results. They are a key feature of functional programming in Kotlin.

… 3 Medium Difficulty Kotlin Interview Questions …

6. What are lambdas in Kotlin?
   Lambdas in Kotlin are anonymous functions that can be treated like values. They can be used as function parameters, return values, and variables.
7. What is the Elvis operator in Kotlin?
   The Elvis operator in Kotlin (?:) is a shorthand way of checking for nullability. It is used to provide a default value when a nullable object is null.
8. What is the difference between “lateinit” and “lazy” in Kotlin?
   “lateinit” is used to declare a non-null variable that will be initialized later, while “lazy” is used to declare a variable that will be initialized only once, when it is first accessed.

… And Finally, 2 Hard Kotlin Interview Questions

9. What is Coroutines in Kotlin? Coroutines in Kotlin are a new way of writing asynchronous and non-blocking code. They allow developers to write asynchronous code that looks like synchronous code, making it easier to understand and debug.
10. What is a sealed class in Kotlin? A sealed class in Kotlin is a special kind of class that can have a limited number of subclasses. Sealed classes are useful when you want to represent a restricted hierarchy of classes, and they allow the use of exhaustive when expressions to ensure that all possible cases are covered in code.

Final Words

Kotlin is a versatile programming language that has gained popularity in recent years due to its concise syntax, null safety, and support for functional programming. Whether you’re new to Kotlin or an experienced developer, it’s essential to understand the language concepts, syntax, and best practices. The 10 interview questions we’ve discussed in this blog post cover a range of topics, from basic concepts like “val” and “var” to more advanced topics like Coroutines and sealed classes. By studying and understanding these questions, you’ll be better prepared to ace your next Kotlin programming language interview and excel as a Kotlin developer. With its many unique features and advantages, Kotlin is sure to remain an important language in the world of software development for years to come.