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

Different ways we can pattern match


Pattern matching in Scala proves to be a very important concept. We can match on variables, constants, and even constructors. We'll take a look at all of them. Let's start with matching against a variable.

Matching a variable

At times, when we have to use the value after the pattern match is successful, we want to match against cases with variables. What this does is it assigns the value to the variable and then we can use that in our code for that particular case. It's better if we look at the following example:

import scala.util.control.NonFatal

def safeToInt(canBeNumber: String): Option[Int] = { 
  try { 
    Some(canBeNumber.toInt) 
  } catch { 
    case NonFatal(e) => None 
  } 
} 
 
safeToInt("10") match { 
  case None => println("Got nothing") 
  case someValue =>  println(s"Got ${someValue.get}") 
} 

The result is as follows:

Got 10 

Here, we have defined a method which tries to convert a number represented by a string to an integer. Then,...