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

Methods


We've already seen Scala methods and used them many times so far. However, to differentiate between methods and functions, we'll take a look at the Scala methods once again. What are methods in Scala? Throughout our discussion of methods, we'll look at several definitions of what a method is. Let's start with what a method may contain:

Method signature

As you can see, we start our method with a few modifiers such as annotations, or keywords such as final and so on. This is followed by a def keyword, method name, parameter list, and then a return type that is optional. Scala methods are intelligent enough to infer the return type. Usually, a return type for a method is what the last expression evaluates to. Check out the following example:

object Methods { 
 
  def filePrinter() = { 
    println("Version 0") 
    val filesHere = (new File(".")).listFiles() 
    for(file <- filesHere) 
      println(file) 
  } 
 
  def main(args: Array[String]): Unit = { 
    filePrinter() 
  } 
 ...