To illustrate how the asynchronous programming model works, we'll get started with a simple example using console.log. Let's get started by adding a couple of console.log statements in a synchronous way. We'll create one console.log statement at the beginning of the app that will say Starting app, and we will add a second one to the end, and the second one will print Finishing up, as shown here:
console.log('Starting app');console.log('Finishing up');
Now these are always going to run synchronously. No matter how many times you run the program, Starting app is always going to show up before Finishing up.
In order to add some asynchronous code, we'll take a look at a function that Node provides called ...