AI, ML & Data Science, SCALA

Scala Basics

by Kinshuk Dutta
This entry is part 9 of 9 in the series Scala Series

Scala Series

Originally posted October 2, 2018 by Kinshuk Dutta

Table of Contents

  1. What is Scala?
  2. Comparison Between Scala and Java
  3. Installing Scala on macOS
  4. Setting Up Your Development Environment
  5. Scala Basics with REPL
  6. Data Types, Variables, and Immutability
  7. Next Steps in Scala Learning

What is Scala?

Scala is a general-purpose programming language that blends object-oriented and functional programming, providing powerful support for concurrency and a strong static type system. It’s designed to be concise and expressive, particularly in comparison to Java. Scala’s compatibility with Java makes it a popular choice in Big Data applications, notably with frameworks like Apache Spark.

Comparison Between Scala and Java

Feature Java Scala
Syntax Complexity Complex syntax Simple syntax
Code Reusability Needs more repetitive code Rewriting is not required
Typing Dynamic in nature Statically typed
Code Reliability Prone to bugs without built-in checks Assurance of fewer defects due to type checks

Key Differences: While both Java and Scala run on the JVM and share some syntax, Scala’s concise syntax and functional programming support allow developers to write cleaner, more reliable code. The static typing in Scala also reduces runtime errors, making it a robust choice for data-centric and performance-sensitive applications.

Installing Scala on macOS

Setting up Scala on macOS is simple, especially with Homebrew. Here’s a step-by-step guide:

Step 1: Verify Java Installation

Since Scala runs on the JVM, ensure Java is installed:

bash
java -version
# Expected output:
# openjdk version "1.8.0-adoptopenjdk"

Or locate Java with:

bash
which java
# Expected output:
# /usr/local/bin/java

Step 2: Install Scala via Homebrew

bash
brew update
brew install scala
brew install sbt # Scala build tool

Once installed, you can verify with:

bash
scala -version

Step 3: Configure SBT for Scala Projects

Adding memory optimizations to sbt:

bash
echo '-J-XX:+CMSClassUnloadingEnabled' >> /usr/local/etc/sbtopts
echo '-J-Xmx4G' >> /usr/local/etc/sbtopts

Setting Up Your Development Environment

For developers used to an IDE, Scala IDE for Eclipse or IntelliJ IDEA (with Scala plugin) are both excellent options for Scala development.

  • Eclipse: Install the Scala plugin via Help → Install New Software..., adding the Scala IDE update site.
  • IntelliJ IDEA: Download the Scala plugin from the plugin marketplace for easy project creation and management in Scala.

Scala Basics with REPL

The Scala REPL (Read-Eval-Print Loop) is a powerful tool for learning and experimenting with Scala code interactively.

To start the REPL, type scala in the terminal. Once inside, you can type expressions, execute them, and see results instantly:

scala
scala> val name = "Scala Learner"
scala> println(s"Hello, $name!")

The REPL provides an immediate, interactive environment, which is particularly helpful when exploring concepts like immutability, pattern matching, and functional transformations.

Data Types, Variables, and Immutability

Scala emphasizes immutability, which means variables declared with val cannot be reassigned:

scala
val immutableVar = 5 // cannot be changed once assigned
var mutableVar = 10 // can be changed

Common Data Types in Scala

  • String: val name: String = "Scala"
  • Integer: val number: Int = 42
  • Boolean: val isScalaFun: Boolean = true
  • List: val nums: List[Int] = List(1, 2, 3, 4)

Function Basics

Functions are first-class citizens in Scala and can be declared as:

scala
def add(x: Int, y: Int): Int = x + y
val result = add(3, 5)

Next Steps in Scala Learning

With this foundational knowledge, you’re ready to dive deeper into Scala. In upcoming blogs, we’ll cover:

  1. Functional Programming in Scala – Discover higher-order functions, immutability, and side-effect-free functions.
  2. Advanced Data Structures – Learn about Scala’s rich collection library, including Maps, Sets, and Tuples.
  3. Concurrency with Scala – Explore actors, the Future API, and other concurrency tools.
  4. Scala and Apache Spark – Harness the power of Scala with Spark for Big Data applications.

Stay tuned as we continue the journey into the world of Scala, exploring its nuances and its applications in modern data-driven environments. Scala’s blend of object-oriented and functional programming makes it a versatile language that’s as powerful as it is elegant!

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