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

Functions versus methods


At the beginning of the chapter, we mentioned that we usually use the terms function and method interchangeably. But the reality is different. In Scala, these two are different concepts altogether. We'll use several examples to help understand this.

We'll take a look at all the differences, from syntactical differences to semantic differences. We'll also look at when to use what: a function or a method. For now, let's use a previous example. For the colorPrinter function, in both versions, we'll define a method and give it the name, colorPrintV3:

val colorPrint = (index: Int) => println(s"Printing Color Page $index.") 
 
 
val colorPrintV2 = new Function1[Int, Unit]{ 
  override def apply(index: Int): Unit = 
    println(s"Printing Color Page $index.") 
} 
 
def colorPrintV3(index: Int) = println(s"Printing Color Page $index.") 

The way we can call these is similar. Syntactically there's no difference:

println("---------Function V1-----------") 
printPages(Document...