Book Image

Learning Scala Programming

By : Vikash Sharma
Book Image

Learning Scala Programming

By: Vikash Sharma

Overview of this book

Scala is a general-purpose programming language that supports both functional and object-oriented programming paradigms. Due to its concise design and versatility, Scala's applications have been extended to a wide variety of fields such as data science and cluster computing. You will learn to write highly scalable, concurrent, and testable programs to meet everyday software requirements. We will begin by understanding the language basics, syntax, core data types, literals, variables, and more. From here you will be introduced to data structures with Scala and you will learn to work with higher-order functions. Scala's powerful collections framework will help you get the best out of immutable data structures and utilize them effectively. You will then be introduced to concepts such as pattern matching, case classes, and functional programming features. From here, you will learn to work with Scala's object-oriented features. Going forward, you will learn about asynchronous and reactive programming with Scala, where you will be introduced to the Akka framework. Finally, you will learn the interoperability of Scala and Java. After reading this book, you'll be well versed with this language and its features, and you will be able to write scalable, concurrent, and reactive programs in Scala.
Table of Contents (21 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Default and parameterized constructors


The primary constructor for any class defined in Scala is the body itself. It means that whatever you declare and define inside a class body gets instantiated when you make an instance of it. There are other ways to define secondary/auxiliary constructors as well. Take a look at the following case classes:

import java.time.LocalDate

case class Employee(name: String, id: String, contact: String, email: String) 

case class StartUp(name: String, founder: Employee, coFounders: Option[Set[Employee]], members: Option[List[Employee]], foundingDate: Option[LocalDate]) 

We can see two case classes named Employee and StartUp. You may wonder why Employee is specific to our StartUp class. The StartUp case class takes a few attributes such as founder, coFounder, members, and foundingDate. So, for creating instances of these case classes, we have to provide values for each member. In this case, if someone on the client side wants to use this case class and does not...