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

For expressions


We would not be wrong, if we say that the for expressions are powerful constructs in Scala. For expressions let you traverse through any collection and perform operations such as filtering and yielding out new collections. We have already gone through this concept in Chapter 3, Shaping Up our Scala Program. Let's recall the example we saw:

object ForExpressions extends App { 
 
  val person1 = Person("Albert", 21, 'm') 
  val person2 = Person("Bob", 25, 'm') 
  val person3 = Person("Cyril", 19, 'f') 
  val persons = List(person1, person2, person3) 
 
  val winners = for { 
    person <- persons 
    age = person.age 
    name = person.name 
    if age > 20 
  } yield name 
 
  winners.foreach(println) 
 
} 
 
case class Person(name: String, age: Int, gender: Char) 

The result is as follows:

Albert 
Bob 

In the previous example, we have a collection of Person objects. We are performing a traversal on the collection and generating another collection consisting of names for...