Lets have a look at an example of what we call callback hell.There are more cool functions availaible with the async module make sure you check them out and use it in your Node.js projects. Im pretty novice in nodejs This is a very easy php example that I want to write in nodejs.Keep in mind that you can still write things synchronously in Node.js, but if openthedoor() did happen to require a callback function, this is what itd look like The callback function will be called after the completion of the task, Node uses a lot of callbacks, Node API supports all callback functions.This greatly improves the performance of Node.js can handle a large number of concurrent requests. Blocking code examples. Node JS anonymous functions and callbacks. Programmatically implementing callbacks with JS/jQuery.When server was run, the application also add some remark on that instructions example porcessid then server is also call callback function app.listen(port[, callback]). Try this example as simple as you can read, just copy save newfile.js do node newfile to run the application. function myNew(next) console.log("Im the one who initates callback") next("nope", "success") Node.js Array Functions.