bout the Author Federico Kereki is a Uruguayan Systems Engineer, with a Master's degree in Education, and over 30 years of experience as a consultant, system developer, and writer. Currently a Subject Matter Expert at Globant, he has taught at Universidad de la República, Universidad ORT Uruguay, and Universidad de la Empresa. He has written articles and booklets on programming, web development, security, and open source topics for blogs, magazines, and websites. He has also written several books, including Modern JavaScript Web Development Cookbook and the upcoming Data Structures and Algorithms in JavaScript. He resides, works, and teaches in Uruguay, but he wrote the first edition of this book while working in India, and the second edition during a sojourn in Mexico. Key Features Apply functional programming concepts and techniques to everyday JavaScript or TypeScript programming Master functional programming in JavaScript and TypeScript to solve real-world development problems Apply functional programming to get better testable programs with higher modularity and reusability Book Description Functional programming is a programming paradigm that uses functions for developing software. This book is filled with examples that enable you to leverage the latest JavaScript and TypeScript versions to produce modern and clean code, as well as teach you to how apply functional programming techniques to develop more efficient algorithms, write more concise code, and simplify unit testing. This book provides comprehensive coverage of the major topics in functional programming to produce shorter, clearer, and testable programs. You’ll begin by getting to grips with writing and testing pure functions, reducing side effects, as well as other key features to make your applications functional in nature. The book specifically explores techniques to simplify coding, apply recursion, perform high-level coding, learn ways to achieve immutability, implement design patterns, and work with data types. By the end of this book, you’ll have developed the practical programming skills needed to confidently enhance your applications by adding functional programming to wherever it’s most suitable. What you will learn Understand when to use functional programming versus classic object-oriented programming Use declarative coding instead of imperative coding for clearer, more understandable code Know how to avoid side effects and create more reliable code with closures and immutable data Use recursion to help design and implement more understandable solutions to complex problems Define functional programing data types with or without TypeScript, add type checking, and implement immutability Apply advanced containers to get better structures to tackle errors and implement async programming Who this book is for If you are a JavaScript or TypeScript developer looking to enhance your programming skills, then this book is for you. The book applies to both frontend developers working with frameworks such as React, Vue, or Angular as well as backend developers using Node.js or Deno. Table of Contents Becoming Functional - Several Questions Thinking Functionally - A First Example Starting Out with Functions – A Core Concept Behaving Properly - Pure Functions Programming Declaratively – A Better Style Producing Functions – Higher-Order Functions Transforming Functions – Currying and Partial Application Connecting Functions – Pipelining, Composition, and More Designing Functions – Recursion Ensuring Purity – Immutability Implementing Design Patterns – The Functional Way Building Better Containers – Functional Data Types