JetBrains Kotlin Interview Questions and answers
Kotlin was introduced in 2011 by JetBrains, who were using Java earlier.There were two reasons behind creating Kotlin, first and foremost is the productivity.
While the second one is the technology that demands evolution each day, which results in coding for the developers also needing some abstraction.
The Kotlin Programming Language is an abstraction of Java with the core principles like Readability, conciseness, safety and ability to tool the language.The goal behind the development of Kotlin was to create an industry language that is used to develop a desktop, web server or mobile application so that Kotlin can be used in any application.
Kotlin focuses on efficiency and dealing with the clutter of software development; adding up on that is now it is officially adopted as a supported language by Android.
This has left the industrialists to look for a candidate with the knowledge of Kotlin.
So, below are a few Kotlin Interview questions that will provide you with the overall structure of Kotlin, its components, and other basics.
These questions might help you crack the interview with ease and get your hands on the job.
1. What is Kotlin?
The features like Range Expression, Extension Function, Companion Object, Smart casts, Data classes are considered to be surplus of the Kotlin Language.
2. Which type of Programming does Kotlin support?
- Procedural programming
- Object-oriented programming
3. Why is Kotlin preferred over Java?
In Kotlin, we code approximately 40% less number of code lines as compared with Java.
4. Where does the Kotlin run and what is the entry point of Kotlin?
5. What are the different types of constructors in Kotlin?
- Primary constructor: It is a section of the Class header and is declared after the class name.
- Secondary constructor: This constructor is declared inside the body.
Note: There can be more secondary constructors for a class.
6. Can you execute Kotlin code without JVM?
7. Mention the structural expressions in Kotlin?
- 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.
8. Explain the data classes in Kotlin?
An object can be initialized in the data class and to access the individual parameters of these data classes, we use component functions.
9. What are the modifiers that are available in Kotlin?
Private: This makes the declaration visible only inside the file containing 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.
10. Can you migrate the code from Java to Kotlin? If yes how do you do it?
11. State the differences between Val and Var?
Var: Var, which is the short form of variable, is a storage location that accepts the reassignment of values that have the same data types.
12. Explain Kotlin’s Null safety?
13, List the Basic data types of Kotlin?
The basic data types in Kotlin are:
14. What are the types of strings available in Kotlin? And, what do you mean by Kotlin String Interpolation?
- Raw string
- Escaped string
In Kotlin String, templates can be evaluated.This evaluation of string templates is called as the string template interpolation.
15. State the advantages and disadvantages of Kotlin?
Kotlin is simple and easy to learn as its syntax is similar to that of Java.
It is the functional language that is based on JVM (Java Virtual Machine), which removes the boilerplate codes. Upon all this, Kotlin is considered as an expressive language that is easily readable and understandable and the performance is substantially good.
It can be used by any desktop, web server or mobile based applications.
Kotlin does not provide the static modifier, which causes problems for conventional java developer.
In Kotlin, the function declaration can be done in many places in the application, which creates the trouble for the developer to understand which function is being called.
Kotlin is a flavor of Java that goes alongside Java.
Many of the Kotlin applications can be built with the integrated parts of Java code.
Thus, most of the Kotlin questions can be answered if you have already acquired the knowledge of Java.