Chapter 1. Reactive programming

This chapter covers

  • Being reactive
  • Thinking about events as streams
  • Introducing Reactive Extensions (Rx)

The reactive programming paradigm has gained increasing popularity in recent years as a model that aims to simplify the implementation of event-driven applications and the execution of asynchronous code. Reactive programming concentrates on the propagation of changes and their effects—simply put, how to react to changes and create data flows that depend on them.[1]


This book is about reactive programming and not about functional reactive programming (FRP). FRP can operate on continuous time, whereas Rx can operate only on discrete points of time. More info can be found at the FRP creator’s keynote,

Get Rx.NET in Action now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.