Scenario Based Interview Questions. There is no specific rule when you can use traits, but there is a guideline which you can consider. Case objects and Case class are serializable by default. A class is a definition for a description. How Scala Solves Diamond Problem? Here, MySingletonObject becomes singleton object automatically. What Is The Use Of Companion Object In Scala? It was developed in Scala. In Stream class, #:: method is used to append a given element at beginning of the stream. scala> var list1 = List(1,2,3,4)list1: List[Int] = List(1, 2, 3, 4). AccountService service = (AccountService) context.getBean("accountService"); Question 32. QUALIFY is like a WHERE clause for windowed records, and will filter out any duplicated records. What Are The Different Types Of Scala Literals? 12,13,14,15,16,17,18,19. The main purpose of these Factory methods in Scala is to avoid using ‘new’ keyword. The only way to retrieve the result is Future.get () in Java. What Are The Java’s Oop Constructs Not Supported By Scala? We cannot change the reference to point to another reference, once the variable is declared using val. What Are Methods Through Which Operation Sets Are Expressed? ReactiveMongo is the best Scala Driver to develop Play/Scala applications to persist data in MongoDB NoSQL data store. There are many jobs related to this across the globe. Question 77. This Elasticsearch example deploys the AWS ELK stack to analyse streaming event data. How Do We Define Instance Members And Static Members In Scala? Nil – It’s a handy way of initializing an empty list since, Nil, is an object, which extends List [Nothing]. Above Person class has one Zero-parameter or No-Parameter or Parameterless Primary constructor to create instances of this class. Divya is a Senior Big Data Engineer at Uber. Question 45. In Scala, we use class keyword to define instance members and object keyword to define static members. Scala is one type of programming language. Scala allows the definition of higher order functions. ‘for/yield’ is used to iterate a collection of elements and generates new collection of same type. What is SSRS and explain its features too? Once a variable is declared using Val the reference cannot be changed to point to another reference. In Java, Inner class is associated with Outer class that is Inner class a member of the Outer class. Question 49. Both isInstanceOf and asInstanceOf methods are defined in Any class. However, there is no interface concept in Scala. In scala, you can define a variable using either a, val or var keywords. Question 7. Scala’s Auxiliary constructor is almost similar to Java’s constructor with few differences. Question 58. Compared to Java’s constructors, Auxiliary constructors have the following few differences: Question 55. Question 35. Question 44. It follows the reverse process of apply method. Scala is a Java-based Hybrid programming language which is the fusion of both Functi 300+ TOP SCALA Interview Questions and Answers 2021 SCALA Interview Questions for freshers experienced :- 1. The difference between “val” and “lazy val” is that “val” is used to define variables which are evaluated eagerly and “lazy val” is also used to define variables but they are evaluated lazily. We can see only first evaluated element and remaining elements are evaluated lazily as shown below: scala> var s1 = Stream(1,2,3,4)s1: scala.collection.immutable.Stream[Int] = Stream(1, ?). Q1). What Are The Scala’s Oop Constructs Not Supported By Java? What Are The Major Differences Between Scala’s Auxiliary Constructors And Java’s Constructors? For example, if we want to create an Employee object  then use the two components  firstName and lastName and compose the Employee object using the apply method. It supports object-oriented, functional and imperative programming approaches. Option has two subclasses: Some and None. Scala is dominating the well-enrooted languages like Java and Python. What Are The Four Types Of Scala Identifiers ? The statement “Scala is hard to master” is definitely true to some extent but the learning curve of Scala for Spark is well worth the time and money. In Java, we use class name to define constructors. Question 5.