JavaScript the Hard Parts: How to Understand Callbacks & Higher Order Functions

Watch Codesmith CEO, Will Sentance dive deeper into callbacks & higher order functions!
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[@laffed2045]

that was pure, great pedagogy. I want this guy to teach me how to make a sandwich just in case I've been missing something profound about putting turkey on bread.

[@ryan.connaughton]

xD

[@mandeeprandhawa8430]

Wow. I have never seen anyone so engaged with the students. He made everything not just fun, but so very simple to understand. This guy is gold!

[@yourdadishere]

Uh, I actually used to be this engaged with my students. It's a sign of pedagogic brilliance.

[@rogut8]

This is what I call The Teacher. Truly great content Sir

[@emilryden8306]

This is absolute top-tier , high-end material for those that are not just out to get a simple quick-n-dirty-done-in-60-sec explanation, but want's to understand the why's and how's of it. 10/10.

[@Codesmith]

Cheers Emil - glad you enjoyed it - we want to do some more content like this -any topics you'd want?

[@emilryden8306]

@@Codesmith As an MSc in Mech. Eng that just started re-schooling myself from supply chain management to coding I really enjoy this teaching approach. takes me back to Uni and the professors that actually were involved and had a passion for the subject. Something magical happens in that room when you explain something on a board in front of others and asking questions. That said, I’m currently doing a course on Udemy called web dev. bootcamp 2021 which is quite broad in its scope, although i feel that alot of topics are either not given their justified time for explanation, or theyre complete word sallads. If it were up to me I would like to have much (if not all) of JavaScript explained like this, from the bottom up. Maybe divide it into different levels (beginner - intermediate - advanced) ? Im convinced from my engineering studies that its not until you explain the basics in such a explicit and straightforward way, that youre able to fully grasp the road and future problems ahead in a much quicker and effective way. Id pay for it.

[@Codesmith]

@@emilryden8306 Thanks Emil - super helpful - there'll be a Node.js one coming soon and React as well hopefully. Congrats btw on the progress you've been making 🙏

[@EmilyHopeGrove]

@@emilryden8306 I so agree, this is what I was hunting for, and couldn't find in among the top results from youtube, hence my comments and like and save and share I just did because I want to help it boost up! Everyone out there reading this in the future, if you found it helpful seriously do all the things I just mentioned because that helps with the SEO end of things for this video. Get it up to the top of the results when searching for callback explanations, it needs to be there!

[@Santon-Motho]

His teachings really make you feel like you've finally set on the real path to the mastery of JS.

[@ryan.connaughton]

Teaching is truly an art. When explained like this it just clicks. Well done, Picasso!

[@latinstuff1]

man I want classes with this man from zero to finish he is so good

[@Me-og5iy]

you are not human, you are god!

[@andreorellana9016]

This guy is an incredible teacher but no teacher could have prevented me from drifting away in my own thought at the part where you said you had a funny story about 'nought' and 0. Please Will, tell us.

[@cannabisanomaly]

Two years and I still want to know what it was

[@JohnBartmannMusic]

More tuts should be this real. Thank you for making me feel more like an actual student of code.

[@arjunvaidy8466]

The best ever explanation for Higher order and callback!!

[@jacked6]

Amazing series!! So detailed and learning a ton.

[@richie.edwards]

It's amazing how much quicker one learns after "digging deep" and understanding the fundamentals well. Thanks @Codesmith

[@theoneandonly6765]

Totally agreed, spending weeks and weeks learning different methods and algorithms only prepares you for specific situations. But learning the WAY that Javascript works helps you to actually understand what is going on, and makes it so much easier to get better at writing code

[@dawid_dahl]

Wow, so happy I found this channel. Instant subscribe for anyone who can teach this well! Excited to watch more videos!

[@gustavomonte6672]

I think MDN should use this guy as a reference when trying to explain a topic.

[@Codesmith]

I'd love to do a video on understand MDN docs at some point

[@jaggyjut]

by far the best training session on callbacks. Really like the step by step walkthrough. Thank you

[@laurenlauren369]

Thank you!! I can finally understand higher order functions!!!

[@procamania]

definitely clears very muddy water. Thank you so much.

[@ronakb1]

This is what I was looking for. Its 2:16 a.m (PT) and now I understand the fundamentals of HOF. Best Explanation Ever. Thank you Codesmith. :)

[@AlexQ6]

This was actually such an excellent, in depth, engaging, step by step lecture. Thank you for uploading it!

[@Pharizer]

Love these videos! Keep them coming, please!

[@minfoodtravels]

i learned more from this video in the first 15 minutes than all the research, reading, and course work. Or maybe this really pushed my brain to actually understand everything ive been working on. Thanks a lot, hope to see another workshop from you.

[@DigAddley]

Amazing work! Taught so clearly and alongside the students to make sure they understand correctly. Only wish my previous teachers put that much effort into concepts like this.

[@ryebass]

Without any hyperbole, this is the THE rigorous explanation of callbacks and higher-order functions I was searching (desperately) for; thanks so much for this!

[@stiffcod5250]

Wow that's fabulous, I mean the way you teach JS is just incredible. You are a real teacher.

[@jfur5881]

Wow, thanks so much for this! I wish I could have you as my teacher.

[@antonyantony7714]

You are the best sir i have been trying to understand this concept flr the past 2 days i only got to understand it after this video

[@tf1n]

Very helpful video! Thank you very much! Your students sound like a sharp bunch, as well.

[@ElvenIvy07]

Brilliant! Loving your videos! :D

[@mcdthedev]

just discovered this channel my goodness thank you was getting more confused from reading MDN docs with no explanations and clarity now if i reread MDN docs this topic will make sense

[@manuelmedina6909]

Excellent Explanation!

[@Lucromick13]

You're a great teacher Will!

[@mydadletsmeshootatcats6754]

Excellent explanation.

[@smallsir7306]

Wow, your videos are extremely good to be free. Thank you so much Sir. If you can teach me JavaScript, I'll be very good at it. Lucky were those guys who were physically under the influence of your voice. You're great Sir

[@womilojuoluwatobi1015]

This teaching is awesome.

[@goodgoodmike]

Awesome explanation, thanks!

[@BNakato]

Great content!!🏅🏅

[@ahstephenson4069]

i've been struggling to get my head around this for the past three evenings, finally makes sense now!! Thank you very much

[@Codesmith]

Really glad it helped :)

[@pheeuh]

He is an amazing instructor!

[@EmilyHopeGrove]

This. All of this. SO detailed. The line by line, bit by bit explanation. Thank you so so much!

[@Codesmith]

You're so welcome!

[@zdargahi]

Best Javascript educator

[@nadineedwards1737]

He's an amazing teacher!

[@psk177]

The absolute BEST!

[@srikanthvaijapur2315]

Loved your explanation sir.. Cleared my confusion.. Thank you❤️ from India

[@mentoriii3475]

i feel lucky that i found your videos 2 years ago, I come back to binge watch your videos from time to time and obviously I highly suggest your videos to all people i know who get into web development

[@Codesmith]

Thank you Mentoriii - hopefully we'll have some new content soon!

[@gilessteiner286]

Great explanation, as always :)

[@rocio9714]

Brilliant! It has been very enlightening for me. Thank you very much😀

[@Codesmith]

Thank you, Rocío!

[@karimmuhammad7051]

How amazing, Really Awesome! Very clear, friendly, and many other good properties as well :> Thank your Master.

[@nkindiafund]

Great video. Does the let i=0 in the for loop create a variable in the local memory of the high-order function? Thx

[@eslpedro]

Thanks for the great explanation about this advanced topics!! Like others said, THIS IS THE BEST VIDEO ABOUT IT IN THE INTERNET!

[@Codesmith]

Thank you, Pedro! We are so happy it was helpful for you!

[@havefun5519]

Cool tut, one step by step guide me from easy to hard.

[@maremeaxi3344]

wow it's the core logic of programing !!!

[@Chris-qg6kc]

13:53 is excellent tactic because it cause everyone to engage vs asking students to raise their hand if they were lost which some may be hesitant to do as it may only be them with a hand up.

[@codellyson]

My favorite teacher.

[@yarvik]

Very good delivery style, delivery structure and, what's the most important to my high maintenance brain, justification for things to exist. Once I know why the hell do I need a higher order function, my brain allows this information to enter its memory store. If your brain is a demanding petulant little prince such as mine, then get your favourite beverage and binge through Will's learning material. After this talk, your brain will no longer have an excuse to reject the information about higher order functions to be stored in it,- it will be persuaded that the above-mentioned information is worth the molecular re-configuration around your synaptic nodes.

[@pannihto7588]

Нихуя ты загнул, братан

[@pulok9909]

you are absolutely correct

[@Emily-gr4nw]

so good! and you sound like derren brown! amazing

[@vladimirstarcevic4870]

Thanks Thanks Thanks and one more Thanks, this is great, that's help me a lot!!! 👍👍

[@lfhbrownify]

Oh man this is what I needed

[@Codesmith]

Thank you!

[@eugeniogarciamason7084]

This was awesome

[@tarek_maza]

This video just gave me the AHA! moment. Thank you Will!

[@Codesmith]

Glad it was useful Tarek 🙏

[@mattwaala]

great pedagogy bro

[@nouralsatari6424]

thank you for existing

[@Codesmith]

Thank *you* for watching Nour!

[@what-do-you-feel]

So, so, so good!

[@Codesmith]

Thank you Konstantin! Let us all know what new topics you want covered if you get a chance

[@abhigullapalli9136]

"i can tell you a funny story..." (glances at camera) "which i will not tell on video, about the confusion that zero and nought can cause" haha i definitely wanna hear this! and thx for the excellent lecture

[@Codesmith]

What a story it is!

[@novanoskillz4151]

can you come to america and teach.. that was amazing.. do you have a javascript course. i would definitely buy... you know how to teach and breakdown and explain in laymans terms.

[@divjay6403]

You are the besttt! Please teach us about the formidable “this” keyword 😲

[@Codesmith]

There's one on how this works - search OOP javascript the hard parts I think

[@divjay6403]

@@Codesmith thank you!

[@cameroncarter6789]

Like with most things worthy of learning I find it interesting that intuitive things like arbitrage or "higher order functions" have nice English words to describe something that should occur inherently....

[@BabyYoda5555]

for the example at 25 minutes what if we don't want to multiply by 2? What if we want to multiply by a user defined number? How would we make this function more dynamic without changing the structure?

[@ARandomPerson--]

The function that gets taken in(iside the parentheses)is the "call back" An outer function that takes in other functions(callbacks) is a higher order function.

[@fardousahmed3883]

Summary of the full video will be found at csx.codesmith.io/units/callbacks/intro-callbacks-read Thanks for this informative video.

[@tauhidxahmed]

Love from Bangladesh

[@noimotalabi4297]

awesome

[@asweeney101]

do for loops open a new execution context in the same way as functions do? When I tested it, the value of i was not accesible after the for loop.

[@imagineabout4153]

I think that for-loops do not create another execution context. They are executed inside the workspace of the execution context in which they are present. I may be wrong, if so please correct me.

[@imagineabout4153]

I now need to know about the funny story 16:54

[@praveens9233]

Why not push() not stacked on call stack?

[@womilojuoluwatobi1015]

Jes!! Where have you been?

[@illiamaksymov5673]

Does for loop create a new execution context?

[@alanhunt3772]

I would say yes because the scope of variables declared within a loop are exclusive to its context. The loop has access to the outer context, but the outer context cannot access the inner context.

[@JD-kf2ki]

How can you run a For Loop on an 'undefined array' ( Line 3)???

[@Khatastrov]

Anyone feel free to correct if i'm wrong here... But on line 3, array is not 'undefined', so far as it's only the argument passed to the copyArrayAndMultiplyBy2() function, it's a placeholder as he said before, the parameter, whatever you call it. But when the function copyArrayAndMultiplyBy2() is called, therefore on line 8, its argument is myArray, which is not undefined, as it equals [1, 2, 3] (it was previously declared on line 7)... Wish it helps a bit ! ;-)

[@filippians413]

I'm here so that I can figure out how to solve a codewars challenge

[@amanrathi]

Gold

[@DDoesT]

I want to know the not point five story.

[@tupperck]

So what's the story about "nought" .5?

[@warrenwong4518]

It finally clicked.

[@jasonvictor1798]

Can someone explain why the function 'multiplyby2' was renamed as instructions?

[@NickHope]

It wasn't renamed as 'instructions'. 'instructions' is the 2nd parameter of the copyArrayAndManipulate function. You can think of it as a placeholder that will be replaced by the 2nd argument that is passed when the copyArrayAndManipulate function is called/invoked/run. In the example at 30:00 he is passing multiplyBy2 as the 2nd argument, so the code of the multiplyBy2 function ITSELF gets passed into the copyArrayAndManipulate function. But he could just as easily have run let result = copyArrayAndManipulate([1, 2, 3]), divideBy2); which would make 'instructions' get replaced by a divideBy2 function (if it existed) as the 2nd argument to the copyArrayAndManipulate function. He could end up with 20 little functions that do different things, such as subtract2, MultiplyByPi etc. and pass any of those into copyArrayAndManipulate. Also important is that the word 'instructions' (which could be any word), as the 2nd parameter of the copyArrayAndManipulate function, matches the word 'instructions' in the body of the function, so the browser knows where to put and run the code of the passed-in function (e.g. multiplyBy2).

[@abhisheksrivastava1208]

how do I ask him to teach JS in India?

[@MadAustinite]

Who else clicked on this video because it looked as if he was wearing a prison jumpsuit in the thumbnail. Teaching JS in prison?

[@paranoidfrandroid]

if you don't return result at the end, does the function still run?

[@Codesmith]

It would still run - but there'd be no output - it was just be held inside the execution context and when the function exits (it inserts a return automatically if you don't add one) everything inside the execution context's local memory would be deleted!

[@paranoidfrandroid]

@@Codesmith ok thank you for the quick response.

[@SuperNZY]

I want to be adopted by Will Sentance.

[@Jurecki07]

Why didnt you declare your myArray varaible before your function?

[@joshuablauvelt9662]

You always declare your variable before you make a reference to them. The function definition itself doesn't use the variable; the variable is passed to the function as an argument when the function is invoked. The invocation is after the variable is declared. You *could* declare the variable before the function and these code examples would still work, but it's a good practice to declare all your functions first so a) they're all in one spot, and b) someone reading your code can glance through you and see all the functions that can/may be used in your program.

[@pritambhattacharya9902]

this guy never asked to liked his video. wow!

[@Codesmith]

😂

[@view1989]

i want to hear that story....

[@Codesmith]

😂

[@alanhunt3772]

Will: "We are going to walk through this function so that we can feel the pain and understand why there's a better way!" me: No we're not, *skips ahead*

[@k0secha]

Amazing instructor. Is it only cis dudes in this class? LOL