Callbacks were the only natively supported way to deal with async code in JavaScript until 2016 ... coordinating multiple asynchronous functions. For example, if we wanted to wait two seconds ...

Node.js is a lean, fast, cross-platform JavaScript runtime environment that is useful for both servers and desktop applications. Scalability, latency, and throughput are key performance indicators ...

However, there still exists Javascript API that requires you to pass in callback accepting functions. For example, ExpressJS requires middleware functions to be plain old functions that accept a next ...

Bear in mind that this function does not return a value. Let’s look at a few examples that might give you an idea of what to do. If you write the same piece of code several times throughout your ...

In reality, all server-side data and functionality can be accessed from the browser using JavaScript ... were handled using JSON callbacks. Using callback functions in APIs should only be allowed ...