Get Programming with Scala

Code, exercises, and answers for the book Get Programming with Scala.

Lessons are grouped per unit. Each lesson is a standalone SBT project and it has the following three packages: listings, quickchecks, trythis.

Have a look at the Table of Contents for links to all the available lessons.

Installation Requirements

Make sure the following tools are installed:

• JDK 8+
• SBT

Running the Code

Code Snippets (Scala Worksheets)

Some lessons are simple snippets (files with extension *.sc) also called Scala Worksheets. They can be interpreted interactively from the REPL by IDEs with dedicated Scala support, such as IntelliJ IDEA and ScalaIDE.

If you a using a text editor or your IDE doesn't support Scala Worksheets, start the REPL from SBT:

sbt console

and evaluate the file as follows:

> :load /path/to/file.sc

Executable SBT Programs

Some lessons are fully fleshed-out programs (files with extension *.scala): in order to run them, they need to be compiled. First, navigate to the folder of the lesson you are interested in.

Suppose you want to review the code for lesson 8:

cd unit1/lesson8

Start SBT:

sbt

Compile and run the code:

> run

If a lecture isn't an executable program, please see section on running Scala Worksheets.

Table of Contents

• UNIT 0: HELLO SCALA!

  • LESSON 1: Why Scala?
  • LESSON 2: Scala – The REPL
  • LESSON 3: SBT – Scala Build Tool

• UNIT 1: THE BASICS

  • LESSON 4: Values and Variables
  • LESSON 5: Conditional Statements and Loops
  • LESSON 6: Function as the most fundamental block of code
  • LESSON 7: Classes as a representation of our world
  • LESSON 8: CAPSTONE 1

• UNIT 2: OBJECT-ORIENTED FUNDAMENTALS

  • LESSON 9: Import and Create Packages
  • LESSON 10: Scope your code with Access Modifiers
  • LESSON 11: Singleton Objects
  • LESSON 12: Traits as interfaces
  • LESSON 13: CAPSTONE 2

• UNIT 3: HTTP SERVICE

  • LESSON 14: Pattern Matching
  • LESSON 15: Anonymous Functions
  • LESSON 16: Partial Functions
  • LESSON 17: HTTP API with http4s
  • LESSON 18: CAPSTONE 3

• UNIT 4: IMMUTABLE DATA AND STRUCTURES

  • LESSON 19: Case classes to structure our data
  • LESSON 20: High Order Functions
  • LESSON 21: What is Purity?
  • LESSON 22: Option
  • LESSON 23: Working with Option: map and flatMap
  • LESSON 24: Working with Option: for-comprehension
  • LESSON 25: Tuple and Unapply
  • LESSON 26: CAPSTONE 4

• UNIT 5: COLLECTIONS

  • LESSON 27: Infix and Postfix Notation
  • LESSON 28: List
  • LESSON 29: Working with List
  • LESSON 30: Set
  • LESSON 31: Map
  • LESSON 32: CAPSTONE 5

• UNIT 6: ERROR HANDLING AND DATA STORAGE

  • LESSON 33: Either
  • LESSON 34: Try: an operation that can fail
  • LESSON 35: Working with Try
  • LESSON 36: Database queries with quill
  • LESSON 37: CAPSTONE 6

• UNIT 7: CONCURRENCY

  • LESSON 38: Future
  • LESSON 39: Working with Future: map and flatMap
  • LESSON 40: Working with Future: for-comprehension
  • LESSON 41: Future and Promise
  • LESSON 42: CAPSTONE 7

• UNIT 8: JSON (DE)SERIALIZATION

  • LESSON 43: Traits as composable block of codes
  • LESSON 44: Lazy values
  • LESSON 45: By Name Parameters
  • LESSON 46: Implicit functions and values
  • LESSON 47: The IO type
  • LESSON 48: JSON (De)serialization with circe
  • LESSON 49: CAPSTONE 8