20 Kotlin Interview Questions with Answers for beginners [2023]
If you want that Kotlin Developer job you always wanted then you have to be equipped with knowledge as far as Kotlin programming language is concerned. This knowledge will help you do well when you face the interview panel on the day for your Kotlin interview .1. What is Kotlin?
Answer: Kotlin is a statically-typed programming language which runs on the JVM. It can be compiled either using Java source code or LLVM compiler.
2. How many constructors are available in Kotlin?
Answer: Two types of constructors available in Kotlin are:
- Primary constructor
- Secondary constructor
- Who is the developer of Kotlin?
- Answer: Kotlin was developed by JetBrains.
3. What are the most important benefits of using Kotlin?
Answer:
- Kotlin language is easy to learn as its syntax is similar to Java.
- Kotlin is a functional language and based on JVM. So, it removes lots of boiler plate
- It is an expressive language which makes code readable and understandable.
4. What are the basic data types used in Kotlin?
Answer: Here is the list of basic data types you will find in Kotlin programming language:
- Strings
- Numbers
- Arrays
- Booleans
- Characteristics
5. Which type of programming does Kotlin support?
Answer: Kotlin supports only two types of programming which are as follows:
- Procedural programming
- Object-oriented programming
6. What are the structural expressions in Kotlin?
Answer: There are three Structural expressions in Kotlin and are as follows:
- Return: It returns from the nearest enclosing function or anonymous function by default.
- Break: This expression terminates the closest enclosing loop.
- Continue: This expression proceeds you to the next closest enclosing loop.
7. What are the modifiers available in Kotlin?
Answer:
- Access modifier in Kotlin provides the developer to customize the declarations as per the requirements. Kotlin provides four modifiers. They are:
- Private: This makes the declaration visible only inside the file containing a declaration.
- Public: It is by default, which means that the declarations will be visible everywhere.
- Internal: This makes the declaration visible everywhere in the same modules.
- Protected: This keeps the declaration protected and is not available for top-level declarations.
8. What is null safety in Kotlin, and why is it important?
Answer:
Null safety is a feature of Kotlin that ensures that variables cannot
be assigned a null value. This is important because it helps avoid
NullPointerException errors, which can be difficult to debug.
9. What are some of the basic syntax rules for Kotlin?
Answer:
Some of the basic syntax rules for Kotlin include the use of semicolons
to terminate statements, the use of curly braces to delimit blocks of
code, and the use of the val keyword to declare immutable variables.
10. What is a lambda expression in Kotlin?
Answer:
A lambda expression is an anonymous function that can concisely
represent a function with a single parameter. Lambda expressions are
often used in conjunction with higher-order functions, such as map and
filter.
11. How do you declare a default argument in Kotlin?
Answer:
To declare a default argument in Kotlin, use the default keyword when
defining a function parameter. This will specify a default value for
that argument, which will be used if no actual value is supplied when
calling the function.
12. Can Kotline offer any additional functionality for standard Java packages or standard Java classes?
Answer:
Kotlin programs can run on standard JVM like any another compiled Java
code. It allows JVM to compile any program to byte-code. It is
accessible using Java Virtual Machine. Therefore, Kotlin is almost
similar to Java. Moreover, Kotlin applications can be built with parts
of Java code.
13. What is the difference between open and public keywords in Kotlin?
Answer:
The keyword “open” refers to the term “open for expansion”. The open
annotation on a class is the polar opposite of the final annotation in
Java: it allows others to inherit from it. By default, a class cannot be
inherited in Kotlin.
In Kotlin, an open method signifies that it can be overridden, whereas it cannot be by default. Instead, any methods in Java can be overridden by default. Also, all the classes are public by default. If no visibility modifier is specified, public is used by default, which means our declarations will be accessible everywhere inside the program.
14. What are the advantages of Kotlin over Java?
Answer: Here are key advantages of Kotlin over Java:
- Data class: In Java, you must create getters and setters for each object, as well as properly write hashCode (or allow the IDE to build it for you, which you must do every time you update the class), toString, and equals. Alternatively, you could utilize lombok, but that has its own set of issues. In Kotlin, data classes take care of everything.
- Patterns of getter and setter: In Java, for each variable, you use it for, rewrite the getter and setter methods. You don’t have to write getter and setter in kotlin, and if you must, custom getter and setter take a lot less typing. There are additional delegates for identical getters and setters.
- Extension Functions: In Java, there is no support for extension functions. Kotlin on the other hand provides support for extension functions which makes the code clearer and cleaner.
- Support for one common codebase: You may extract one common codebase that will target all of them at the same time using the Kotlin Multi-Platform framework.
- Support for Null Safety: Kotlin has built-in null safety support, which is a lifesaver, especially on Android, which is full of old Java-style APIs.
- Less prone to errors: There is less space for error because it is more concise and expressive than Java.
15. What is the difference between a data class and a regular class in Kotlin?
Answer:
A data class is a class intended to hold data. A regular class is a
class that can perform arbitrary operations. Data classes are typically
simpler and more efficient than regular classes.
16. How do you declare a function in Kotlin?
Answer:
To declare a function in Kotlin, use the fun keyword followed by the
name of the function and the parameters that it accepts. You can then
define the function body within curly braces.
17. What is the difference between a suspend function and a regular function?
Answer:
A suspend function can be suspended, meaning that you can pause its
execution and resume it at a later time. A regular function cannot be
suspended and will always execute to completion.
18. What are coroutines in Kotlin?
Answer:
Coroutines is one of the amazing Kotlin features that allow for concurrent or parallel
execution of code. Coroutines can improve application performance by
taking advantage of multiple cores in a processor.
Here is a nice diagram which shows how you can use multiple coroutine inside each thread in a Kotlin application:
19. How do you cancel a coroutine in Kotlin?
Answer:
Call the cancel function on the CoroutineScope object to cancel a
coroutine in Kotlin. This will cancel the coroutine and free up any
resources.
20. What is type inference in Kotlin?
Answer:
Type inference is the process of automatically determining the type of a
variable or expression based on its value. In Kotlin, type inference
determines the type of variables when they are first declared and the
return type of functions.
That's all about the frequently asked Kotlin Interview Questions and answers for beginners and experienced Java developers. You must now be more than ready
to handle the Kotlin interview that is awaiting you.
You are at a better position as far as passing your interview is concerned. This is because you have found the right questions with answers that you will face during the interview. Just make sure you master everything and you will smile all day.
I have purposefully not included more in-depth Kotlin question in this article but if you guys would like, I can do that, just let me know your experience in comments. You can also share any Kotlin question you may have or something which was asked to you and you couldn't answer during interview.- 20 Docker Interview Questions with Answers
- 25 DevOps Interview Questions with Answers
- 20 Kubernetes Interview Questions with answers
- 40+ Object-Oriented Programming Questions with Answers
- 20 Software Design and Pattern Questions from Interviews
- 50+ Microsoft SQL Server Phone Interview questions
- 15 Cyber Security Interview Questions with Answers
- 20 PostgreSQL Interview Questions with Answers
- 12 SQL Query Interview questions with solutions
- 25+ Spring Security Interview Questions with Answers
- 20 Algorithms Interview Questions for Software Developers
- 130+ Java Interview Questions with Answers
- 17 Spring AOP Interview Questions with Answers
- 25 Recursion Interview questions with answers
- 30 JavaScript Interview Questions with Answers
- 21 Chef Interview Questions with Answers
- 10 Oracle Interview Questions with Answers
- 20+ Spring Boot Interview Questions with Answers
- 20 JUnit Interview Questions with Answers
- 50 SQL and Database Interview Questions for Beginners
- 35 Python Interview Questions for 1 to 2 years experienced
No comments :
Post a Comment