10 Popular Kotlin Interview Questions

• Kotlin is a very practical language. It covers the issues that developers face, rather than those of academics. So it has type inference, fantastic type safety, a good collection library, and, to top it off, a concurrency library.
• And now it’s official: many companies are switching their backend applications to Kotlin, and this trend isn’t going away anytime soon. Follow through to see the most thorough and up-to-date list of the most popular and complex Kotlin Interview Questions that every Android developer should know in 2020.

1.  In Kotlin, how do you initialize an array with values?

Ans.  The Kotlin array initialization code is as follows :

val numbers: IntArray = intArrayOf(10, 20, 30, 40, 50)

2. What is the difference between var and val in Kotlin?

Ans.  Var is a mutable variable in Kotlin that can be assigned multiple times and is similar to a general variable.

In Kotlin, val is similar to a Final variable. It is immutable and can only be initialized once.

3. Where should I use var and where val?

Ans.   When the value changes frequently, use var.
When there is no change in value over the entire class, use val.

4. On Android, how does Kotlin work?

Ans.  Kotlin’s code is compiled into Java bytecode and executed at runtime by the Java Virtual Machine, or JVM, just like Java code.

5.  What is the difference between declaring variables using val and declaring variables with const?

Ans.  The variables declared with the val and const keywords are both immutable. The value of the const variable, on the other hand,                must be known at compile time, but the value of the val variable can be assigned at any time.

6.  Is there a ternary operator in Kotlin, like there is in Java?

Ans.   No, we don’t have a ternary operator in Kotlin, however you may use the if-else or Elvis operators to simulate the functionality of             a ternary operator.

7.  What is the process for converting a Kotlin source file to a Java source file?

Ans.

To convert your Kotlin source file to a Java source file, follow these steps:

1. In IntelliJ IDEA / Android Studio, open your Kotlin project.
2. Select Tools > Kotlin > Show Kotlin Bytecode from the drop-down menu.
3. To extract your Java code from the bytecode, click the Decompile button.

8. What is a data class in Kotlin?

Ans.  Data classes are classes created only for the purpose of storing data. It’s referred to as data in Kotlin. As an example, consider the

following:

When a class is marked as a data class, you don’t need to implement or construct the following methods, like we do in Java:                        hashCode(), equals(), function toString() { [native code] }(), copy (). Because the compiler generates them internally, the code is              also clean.

9. In Kotlin, can we utilize basic types like int, double, and float?

Ans. We can’t utilize primitive types directly in Kotlin. As an object wrapper for primitives, we may utilize classes like Int, Double, and so on. However, these primitive types are present in the produced bytecode.

10.  What is String Interpolation in Kotlin?

Ans.  String Interpolation is useful if you want to utilize a variable or conduct an operation on a string. You can use the $ sign to                           reference a variable in the string or to conduct an operation in the space between the $ and the sign.

e.g.

  var name = “Nullclass”

  print(“Hello! I am learning from $name”)

So these were some of the most asked interview questions related to Kotlin, hope you had a good understanding of the pattern.

Furthermore, if you are interested in learning through real-time projects on developing apps similar to Netflix, WhatsApp etc.

Be sure to check out our courses at Nullclass.

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