Scala Study Notes

Anonymous Functions and Lambdas

Master Scala's lambda syntax, underscore shorthand, and closures for writing concise inline functions used throughout collection operations.

Building a REST API with Scala

A hands-on guide to building a JSON REST API in Scala using a typical HTTP toolkit, covering routing, JSON codecs, and error handling.

Case Classes Explained

Understand what case class generates for free -- structural equality, copy, and pattern matching support -- and how pairing it with sealed traits builds safe,…

Classes and Objects in Scala

Learn how Scala classes bundle state and behavior, how primary and auxiliary constructors work, and how singleton objects and companion objects replace Java's…

Conditionals and Match Expressions

Understand how Scala treats if-else and match as expressions that return values, including pattern matching on case classes and sealed traits.

Error Handling with Try and Either

Scala models recoverable failure as ordinary values using Try and Either, letting you compose error-prone code with map, flatMap, and for-comprehensions instea…

Functions in Scala

Learn how to define, call, and structure functions in Scala using def, including default parameters, named arguments, and multiple parameter lists.

Futures and Concurrency

Scala's Future abstraction models asynchronous computations that run on an ExecutionContext, letting you compose non-blocking operations with map, flatMap, and…

Higher-Order Functions

Learn how Scala functions that accept or return other functions enable powerful, reusable abstractions like map, filter, fold, and currying.

Implicits in Scala

Scala's implicit parameters, implicit conversions, and implicit classes let the compiler thread context and behavior through code automatically, powering type…

Lists in Scala

Learn how Scala's immutable List works as a singly-linked structure, how to build and traverse it, and the core operations every Scala developer uses daily.

Loops and For-Comprehensions

Explore Scala's imperative loop constructs alongside the functional for-comprehension, including guards, nested generators, and yield-based transformations.

map, filter, and reduce

Master Scala's core higher-order functions for transforming, selecting, and aggregating collections declaratively instead of writing manual loops.

Maps and Sets

Understand Scala's Map and Set collections - how they guarantee unique keys and elements, the difference between immutable and mutable variants, and their core…

Mutable vs Immutable Collections

Understand Scala's two parallel collection hierarchies, why immutability is the default, and when it's worth reaching for a mutable collection instead.

Option and Null Safety

Learn how Scala's Option[T] replaces null with a compiler-checked container type, covering map/flatMap/getOrElse, for-comprehensions, and safe Java interop.

Pattern Matching in Depth

Go beyond basic match expressions to guards, type patterns, list deconstruction, custom extractors, and compiler-checked exhaustiveness over sealed hierarchies.

Scala and Akka Actors

Akka's actor model gives Scala developers a way to build concurrent, distributed systems out of isolated, message-driven actors instead of shared mutable state…

Scala and Apache Spark

Apache Spark's Scala API exposes distributed, fault-tolerant data processing through RDDs, DataFrames, and Datasets, letting Scala code scale from a laptop to…

Scala Best Practices

Idiomatic patterns for writing clean, maintainable, and performant Scala code, from immutability to error handling to project structure.

Scala Interview Questions

Frequently asked Scala interview topics — from core language features to collections, concurrency, and functional programming concepts — with the reasoning int…

Scala Operators and Expressions

How Scala treats operators as method calls, covers arithmetic, comparison, and logical operators, and why almost everything in Scala is an expression that retu…

Scala Quick Reference

A condensed cheat sheet of core Scala syntax — variables, collections, pattern matching, and common idioms — for quick lookup while coding.

Scala vs Java

A practical comparison of Scala and Java covering syntax, type systems, concurrency, and when to choose one over the other on the JVM.