Functional Programming with TypeScript

Introduction

The book "Functional Programming with TypeScript" (by Joon Young Park, 2022, 260 pages) is a modern practical guide that helps developers master functional programming (FP) using TypeScript. Unlike many abstract textbooks, this book focuses on specific techniques and patterns that can be immediately applied in real projects. TypeScript, being a strictly typed superset of JavaScript, is ideal for implementing functional ideas: its type system allows expressing many FP concepts at compile time, not just at runtime.

What the book is about

The book progressively covers fundamental and advanced topics of functional programming. The author starts with basic principles: pure functions, immutability, absence of side effects. Then moves on to more complex constructs: higher-order functions, currying, function composition, functors, monads (Maybe, Either, IO), and working with asynchrony in a functional style. Special attention is given to practical aspects: how to organize code to keep it readable and testable, how to use TypeScript for safe data modeling (algebraic data types, discriminated unions).

Who this book is for

The book is aimed at developers already familiar with TypeScript (or JavaScript) at an intermediate level. It will be useful for:

• Frontend and backend developers