Asynchronous Programming – The End of The Loop

To become an effective JavaScript programmer, it is important for a developer to learn how to develop and maintain asynchronous programs. JavaScript is a single-threaded programming language due to which applications written in JavaScript must use async APIs to stay responsive to user inputs while performing long-running tasks such as making a request for data from a server or running animations. You can’t get very far in a JavaScript code base without running across an asynchronous API.

Asynchronous programming may seem intimidating. How can we write programs that accepts input from the user, runs an animation, and sends a request to the server over the same period of time? How do we keep the code base clear and concise? How do we gracefully propagate and handle asynchronous errors? How can we avoid memory leaks caused by dangling event handlers? The different kinds of loops i.e. `for`, `for/in`, `while` and `do/while` and `try/catch/finally` statements in JavaScript are no help since they only work on synchronous functions.

Asynchronous programming is much easier than it seems and the key to it is to think differently about events. By using a handful of simple functions it is possible to build asynchronous programs. The first secret towards mastering asynchronous programming is learning to write programs without making use of loops. JavaScript loops can only work synchronously, and therefore cannot be used to repeat asynchronous functions. In order to gain expertise in asynchronous programming we must first learn how to code without making use of loops.

In the upcoming 9 posts to follow we will learn how to program Arrays without loops using just a few simple functions. We will learn the correct approach towards asynchronous programming and avoid making common mistakes. By the end of these 9 posts we will have the tools, concepts, and libraries required to be an asynchronous programming expert!