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This article mainly introduces "what are the Kotlin interview questions". In the daily operation, I believe many people have doubts about the Kotlin interview questions. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful for you to answer the questions of "what are the Kotlin interview questions?" Next, please follow the editor to study!

Question 1: what is Kotlin?

It is an open source programming language that combines object-oriented programming capabilities. Scope expressions, extension functions, concomitant objects, intelligent transformations, data classes and other functions are considered to be features of the Kotlin language.

Question 2: who developed kotlin?

Kotlin is developed by jetbrains.

Question 3: why should we switch from Java to kotlin?

First of all, kotlin is simpler than Java. It removes a lot of redundant code from Java. Kotlin provides many features that Java does not have.

Question 4: talk about the three benefits of using kotlin.

Kotlin is easier to learn because it is very close to Java.

Kotlin is a functional programming language based on jvm.

The kotlin code is easier to read and understand.

Question 5: explain the extension function.

The extension function is used to extend class without deriving from class.

Question 6: what does null safety mean in kotlin?

The feature of null safety is to remove the risk of null pointer exception in real-time operation. It is also used to distinguish between null and non-null references.

Question 7: why are kotlin and Java interoperable?

Because there is no difference between these two languages for jvm. They are all compiled into byte code and then run on jvm.

Question 8: is there a ternary conditional operator in kotlin?

Does not exist, there is no ternary conditional operator in kotlin.

Question 9: how to declare a variable in kotlin?

Val xyz:String

Question 10: how many constructors are there in kotlin?

There are two kinds, one is the primary constructor, the other is the secondary constructor.

Question 11: what type of programming does kotlin support?

One is procedural programming, the other is object-oriented programming.

Question 12: talk about the extension of Java.io.file in kotlin.

BufferedReader.

ReadBytes.

ReadText

ForEachLine

ReadLines

Question 13: how to handle null exceptions in kotlin?

Use the elvis operator to handle null exceptions.

Question 14: what are the characteristics that kotlin has, but Java does not?

Null safety.

Operator overloading.

Coroutines.

Range expressions.

Smart casts.

Companion objects.

Question 15: explain the role of data classes in kotlin.

The data class contains basic data types and does not contain any functional functions.

Question 16: can we convert Java code into kotlin code?

Yes, we can use jetbrains ide to convert Java code into kotlin, or we can use Android studio to convert.

Question 17: does kotlin allow macros?

It's not allowed. Kotlin does not support macros.

Question 18: talk about the default behavior of the kotlin class.

The kotlin class is final by default. Because kotlin supports multiple class inheritance. Open classes are much more expensive than final classes.

Q19: does kotlin support raw data types?

No, kotlin does not support raw data types.

Question 20: what is the range operator?

The Range operator is used to traverse a range. Expressed in terms of two points.

For (I in 1.. 15)

Print (I)

Question 21: does kotlin provide additional functionality for standard Java libraries and classes?

The kotlin program runs on a standard Java virtual machine. So there is little difference between kotlin and Java at this level. Java code can also be used directly in kotlin programs.

Question 22: define a volatile variable in kotlin.

Volatile var x:Long?=null

Question 23: what is the purpose of abstractions in kotlin?

Abstraction is the most important concept in object-oriented programming. The characteristic of an abstract class is that you know what the class will do, but you don't know exactly how and what it does.

Question 24: how do I compare two strings in kotlin?

In the first way, you can compare two strings with a double equal sign.

The second method uses String.compareTo, an extension function, to compare two strings.

Question 25: what is the following code for?

Bar {

System.out.println ("")

}

Bar, as a function, is receiving an expression as an argument, which is used to print a line of strings.

At this point, the study of "what are the Kotlin interview questions" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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