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

Function literals


A function literal, in simple terms, is a representation of an action that can be performed to specify the input and output parameter types:

(value1: Int, value2: Int) => Int 

This line represents a function literal, which is easily readable. It displays a function that takes two values, value1 and value2 of type Int, and returns another, Int. We've seen some examples of it, such as our ColorPrinter example where we were simply able to print color as well as simple black and white pages using just one function named printPages:

def printPages(doc: Document, lastIndex: Int, print: (Int) => Unit) = if(lastIndex <= doc.numOfPages) for(i <- 1 to lastIndex) print(i) 
 
val colorPrint = (index: Int) => println(s"Printing Color Page $index.") 
                                        
val simplePrint = (index: Int) => println(s"Printing Simple Page $index.") 
 
println("---------Method V1-----------") 
printPages(Document(15, "DOCX"), 5, colorPrint) 
 
println("...