Conclusion

[MUSIC] 0:00 Well done. 0:04 Callbacks can be challenging but they're a powerful tool in asynchronous, 0:05 event based programming. 0:09 They're everywhere in JavaScript. 0:11 I encourage you to take the course again if you're still having problems 0:13 surrounding callbacks. 0:17 The second time through, there may be some more a ha moments. 0:18 Let's recap on some of the things that you've learned. 0:22 Functions are often referred to as first class objects in JavaScript. 0:25 All this means is that a reference to the function can be passed around 0:29 just like any other variable. 0:33 Remember, a callback function is like any other. 0:35 Instead of call by you in the code it's being triggered by a system event. 0:39 In the case of setTimeout, 0:44 the callback is invoked after a delay which is supplied as a second argument. 0:46 Remember, you don't include parenthesis when you pass in the name of 0:51 the functioning since that would invoke the function immediately. 0:55 Callbacks can be expressed as an anonymous function too or an arrow function. 1:00 Some callbacks can have arguments passed in. 1:06 In the case of the addEventListener, 1:09 the callback can have a single argument passed in, the event object. 1:12 Callbacks are everywhere in JavaScript, whether you stay in the front-end, or 1:17 move over to the back-end with Node.js. 1:21 You'll encounter them in all of your JavaScript developer life. 1:23 I hope you enjoyed this course, and until next time, keep on coding. 1:27