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 book 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: The Scala Environment
  • LESSON 3: sbt – Scala Build Tool

• UNIT 1: THE BASICS

  • LESSON 4: Values and Variables
  • LESSON 5: Conditional Constructs 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 - The Vending Machine

• 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 - What time is it?

• 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- The Time HTTP Server

• UNIT 4: IMMUTABLE DATA AND STRUCTURES

  • LESSON 19: Case classes to structure our data
  • LESSON 20: Higher 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 - Rock, Paper, Scissors, Lizard, Spock!

• UNIT 5: LIST

  • LESSON 27: List
  • LESSON 28: Working with List: map and flatMap
  • LESSON 29: Working with List: properties
  • LESSON 30: Working with List: element selection
  • LESSON 31: Working with List: filtering
  • LESSON 32: Working with List: sorting and other operations
  • LESSON 33: CAPSTONE 5 – The Movies Dataset

• UNIT 6: OTHER COLLECTIONS AND ERROR HANDLING

  • LESSON 34: Set
  • LESSON 35: Working with Set
  • LESSON 36: Map
  • LESSON 37: Working with Map
  • LESSON 38: Either
  • LESSON 39: Working with Either
  • LESSON 40: Error Handling with Try
  • LESSON 41: CAPSTONE 6 – The Library Application

• UNIT 7: CONCURRENCY

  • LESSON 42: Implicit and Type Classes
  • LESSON 43: Future
  • LESSON 44: Working with Future: map and flatMap
  • LESSON 45: Working with Future: for-comprehension and other operations
  • LESSON 46: Database queries with Quill
  • LESSON 47: CAPSTONE 7 – The Quiz Application: Part 1

• UNIT 8: JSON (DE)SERIALIZATION

  • LESSON 48: JSON (De)serialization with circe
  • LESSON 49: Lazy Evaluation
  • LESSON 50: The IO type
  • LESSON 51: Working with the IO type
  • LESSON 52: Testing with ScalaTest
  • LESSON 53: CAPSTONE 8 – The Quiz Application: Part 2