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

Packaging and importing


One of the important aspects of object-oriented programs is how we define modular, reusable, and hierarchical structures. We're allowed to put all the code that we write, constructs like classes, traits, and objects, in some particular package. By using packaging and visibility rules, we can make our code more to reason about, means to expose some method to other classes or  and we get structured and modular code as an added advantage. There are a couple of ways you're allowed to write package statements in Scala; we'll take a look at those.

Package statements

We can write package statements at the beginning of the file. One of the simplest examples is as follows:

package country 
 
class Country(val name: String) { 
  import Country._ 
 
  val populationsMap  = scala.collection.mutable.Map[Int, Double]() 
 
  def showAveragePopulation() = println(averagePopulation(this.populationsMap.values))
 } 
 
object Country {
   def averagePopulation(populations: Iterable[Double...