Introduction to Scala Interview Questions And Answers
Scala is a general-purpose programing language providing support for functional programming and a strong static type system. I was designed by Martin Ordersky, and it has first appeared on 20 January 2004. The file extension is scala or .sc. Scala combines object-oriented and functional programming in one concise, high-level language. Scala’s static types help avoids bugs in complex applications, and its JVM and JavaScript runtimes let you build high-performance systems with easy access to huge ecosystems of libraries. It runs on Java platforms.
Example
Hello, world program In Scala will be written like this:
Program:
object HelloWorld extends App {
println(“Hello, World!”)
}
For Compiling: scalac HelloWorld.scala
Running: scala HelloWorld.
So if you are looking for a job that is related to Scala, you need to prepare for the Scala Interview Questions. Though every Scala interview is different and the scope of a job is also different, we can help you out with the top Scala Interview Questions and Answers, which will help you to take the leap and get you success in an interview.
Below is the Scala Interview Questions that are mostly asked in an interview; these questions are divided into two parts:
Part 1 – Scala Interview Questions (Basic)
This first part covers basic Scala Interview Questions and Answers.
1. What is Scala?
Answer:
Scala stands for Scalable Language. It is a multi-paradigm programming language. It supports both Object-oriented and functional programming languages. Its runs for JVM(Java Virtual Machine).
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2. What are the major advantages of Scala?
Answer:
The major advantages of Scala language are: Very precise code, flexible syntax, Supports all OOP features, More reusable code, highly productive.
3. Give some examples of JVM Language?
Answer:
Java, Scala, Groovy, and closure are very popular for the JVM language.
4. What is the superclass of all classes in Scala?
Answer:
“Any” class is the superclass of all classes in Scala.
5. What is the default access modifier in Scala?
Answer:
“Public” is the default access modifier in Scala.
6. What is similar between Scala Int and Java’s java.lang.integer?
Answer:
Both are used to define Integers, both are classes, and both are 32-bit signed integers.
7. What is Null in Scala?
Answer:
Null is a Type in Scala. It is available in Scala package as “scala. Null”.
Let us move to the next Scala Interview Questions And Answer.
8. What is the Unit in Scala?
Answer:
In Scala, a unit is used to represent “No value” or “No Useful value”. In the package, it is defined as “scala. Unit”.
9. What is the val and var in scala?
Answer:
Var is standing for variable, and Val is standing for value. Var is used to define. Mutable variable and value can be reassigned after the creation of it. Val is used to defining Immutable variables, which means the value cannot be reassigned once it’s created.
10. What is REPL in Scala?
Answer:
REPL stands for reading Evaluate Print Loop. Generally, we called it “Ripple”. It is an interpreter to execute scala code from the command prompt.
11. What is Scala “If..else”?
Answer:
Scala “If. Else” is an expression. We can be assigned it to a variable. For EG:
val year = if( count == 0) 2014 else 2015
12. What do you mean by Scala Map?
Answer:
This is the basic Scala Interview Questions that is asked in an interview. Scala map is a collection of key-value pairs wherein the value in a map is retrieved using a key. Values in a map are not unique, but keys are unique.
There are two types of maps: Mutable and Immutable.
13. What do you understand by a closure in Scala?
Answer:
The closure is the function in scale where the returned value of the function depends on the one or more than one variable which is defined outside the function.
Part 2 – Scala Interview Questions (Advanced)
Let us now have a look at the advanced scala Interview Questions.
14. What do you mean by Option in Scala?
Answer:
It is used for wrapping the missing value.
15. What is Scala Trait?
Answer:
It’s a special kind of which enables Multiple Inheritance. For Eg:
trait MyTrait {
deff()
}
16. Give some examples of packages in Scala.
Answer:
lang, scala, scala.PreDef is the packages in Scala.
Let us move to the next Scala Interview Questions And Answer.
17. What is the use of tuples in Scala?
Answer:
Scala tuple is used to combine the fixed number of the item together. Nature vice the tuple are immutable and can hold objects of different types. For Eg: Val myTuple = (1, “element”, 10.2)
18. What is the Monad in Scala?
Answer:
A Monad is an object in Scala which wraps another object.
19. In Scala, how you will format a string?
Answer:
By the following way:
Val formatted= “%s %i”.format (mystring.myInt)
20. What are Scala Identifiers?
Answer:
There are four types of Scala Identifiers:
Alphanumeric identifiers
Operator identifiers
Mixed identifiers
Literal identifiers
21. What are the different types of Literals in Scala?
Answer:
The literals in scale are given below:
Integer Literals
Floating-point literals
Boolean Literals
Symbol Literals
Character Literals
String Literals
Multi-Line Stings
22. What is the latest version of Scala?
Answer:
Scala 2.12, which requires Java 8.
Let us move to the next Scala Interview Questions And Answer.
23. Which keyword is used to define a function in Scala?
Answer:
def keyword is used to define the function in Scala.
24. Differentiate Object and Class in Scala?
Answer:
An object is a singleton instance of the class. It does not need to initiated by the developer.
25. What do you mean by Akka in Scala?
Answer:
Akka is a concurrency framework in Scala which uses Actor based model for building JVM application.
26. How to compile and run a scala program?
Answer:
Scala compiler scalac to compile Scala Program and scala command to run it.
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This has been a guide to the List of Scala Interview Questions and Answers. Here we have covered the few commonly asked interview questions with their detailed answers so that it helps candidates to crack interviews with ease. You may also look at the following articles to learn more –
