Top 25 Kotlin Interview Question Answers πŸ™‚

Introduction
 
Here is a list of the top 25 Kotlin programming interview questions and answers. 
 
Q1. What is Kotlin Programming?
 
Kotlin is a general-purpose, statically typed and open-source programming language. It runs on JVM and can be used anywhere where Java is used today. It is used to develop Android mobile apps.
 
Kotlin was developed by JetBrains and its team. Kotlin project was started in 2010 and it was developed under the Apache 2.0 license. 
 
Q2. What is the current version of Kotlin?
 
The current version of Kotlin 1.3.61
 
Q3. How do you declare variables in Kotlin?
 
Kotlin variable is declared using keywords Var and Val.
 
We can declare variables in Kotlin with two ways,
 
1. var language="Java" // var is a string type declare variables
2. val salary= 30000 // and val is a Int type declare variables
 
 
Q4. What is the difference between var and val variables?
 
Var – Variable – A multi-purpose variable that stores a value but the type of the variable or the value can be changed. A different data type can be stored in the same variable. 
Val – Value – The value type variable can store the type of the value that was put away in val, but couldn't shift in time. When alloted, just the val gets read, similar to a consistent in Java Programming language. The properties of the article (as Val) could be changed, yet the item itself is perused only.
 
Allot and change estimation of Var for an essential information type
 
Q5. What’s Null Safety in kotlin
 
Invalid Safety in Kotlin is to dispose of the danger of the event of NullPointerException continuously. On the off chance that you are a Java designer, you may have unquestionably run over the barbarities of NullPointerException it makes during constant.
 
Q6. what is the difference between print() and println().
 
The difference between print() and println():-
1. print() in this method used to print valus provided inside the method"()".
2. println() mehtod is used to print values provided inside the method "()" and moves cursor to the beginning of next line.
 
Q7. How many types are used in kotlin?
 
there are to type function used in kotlin:
1. Standard library function
2. User-defined function
 
Q8. What is the Standard library function and User-defined function?
 
1. A standard library function is built-in library functions that are implicitly present in the library and available for use.
2. A user-defined function is a function that is created by the user. User-defined function takes the parameters(s), perform an action and return the result of that action as a value
 
Q9. What is the Inline Function in Kotlin?
 
An inline function is declared with a keyword inline. The use of inline function enhances the performance of higher-order functions. The inline function tells the compiler to copy parameters and functions to the call site.
 
Q10. What are the features you think are there in Kotlin but not in Java?
 
Kotlin has a lot of highlights that Java doesn't.
1.Coroutines
2.Companion Objects
3.Data classes
4.Operator Overloading
5.Range expressions
6.Smart casts
7.Null Safety
8.Extension Functions
Note: There are many features but we write some of the best features
 
Q11. What are some build tools to support Kotlin?
 
1.Gradle
2.Maven
3.Ant
4.Kobalt
 
Q12. Tell me some company names of those using Kotlin,
 
GitHub repositories or talks include Square, Pinterest, Basecamp or Corda company are using Kotlin
 
Q13. How can you check if two Strings are equivalent esteemed?
 
We can cheek if tow stings are equivalent esteemed using of Using == (double equal to) operator.
 
Q14. Is there a Ternary Conditional Operator in Kotlin like in Java?
 
No, the ternary conditional operator in Kotlin is not like Java but is very different from it
 
Q15. Explain Higher-Order Functions?
 
Higher-Order Function is a function that takes functions as parameters or returns a function.
 
Q16. How Can you execute Kotlin code without JVM?
 
We can execute JVM, which stands for Java Virtual Machine is a feature of Kotlin. This feature compiles a Kotlin code into a native code, which can be done without JVM too.
 
Q17. Why we use const and val in Kotlin?
 
We Use Const because the Keyword const is used for compile-time initializations.
Val Keyword is used for runtime initialization
 
Q18. Tell some key modifiers that are associated with Kotlin?
 
1.public
2.private
3.protected
4.interval
 
Q19. What are the benefits of Kotlin?
 
Some benefits of Kotlin:
 
1. Syntaxually resembles Java and it is also easy to learn a language
2. A functional language built-in reference to JVM
3. Code readability and understandability is very high
 
Q20. How to handle a null operator?
 
We can handle all the nullable values using the Elvis operator.
 
Q21. What is mean by init block?
 
Init is a login square and it is executed in the essential constructor and initialized. On the off chance that you need to deny in the auxiliary constructor, at that point it begins working after essential constructor in the chain structure.
 
Q22. What we use in substitution to switch explanation in Kotlin?
 
We use when in kotlin instead of the switch in java:-
When(x)
{
caseA: code executed if x=A:
break:
caseB: code executed fi x=B:
break;
Default code executed if x does not match any case
}
 
Q23. What are the structural expressions in Kotlin?
 
There are three important structural expressions in Kotlin:
 
1. Break: break articulation breaks the nearest encasing circle
2. Return: This articulation comes back from the nearest capacities or default capacities.
3. Proceed: This articulation continues for the following circle.
 
Q24. Can we execute Kotlin code without JVM?
 
JVM, which represents Java Virtual Machine is an element of Kotlin. This element incorporates a Kotlin code into a local code, which should be possible without JVM as well.
 
Q25. What’s the type of the following Array? val arr = arrayOf(1, 2, 3);
 
The type is Array<Int>. That’s all for Kotlin interview questions and answers.
 
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