Javascript 30 days

30 Days of Flutter - Kick Off - #30DaysOfFlutter

30 Days of Flutter - Kick Off - #30DaysOfFlutter1 Feb. 2021
59 884

Event details can be found

Event details can be found here: https://goo.gle/30daysofflutter

Comments (79)
Viet Nguyen Tran

thank you for your great event, resource list, ... Thank you very much

Mapp Inc

What a beautiful community! <3

Debaian Acolyte

I wanna ask can we develop an app using flutter framework, in any editor in our android mobiles?


really nice series

abhi varshi

When will the Flutter web support hot reload ?. Now we have only hot restart.

Sonika Punit Goyal

#30DaysOfFlutter hey can u please describe all about splashscreen

Ahmd Asml

We need to translate into Arabic

Roshan nahak

Wooho great session

Jeremy Kenn

crap, i'm late.. ><

Murtaza Mukhtar

Very Helpful.
Thank you all.

Ritik Kumar

#30DaysOfFlutter how can i install the debug application wihich i make in this workshop in the samsung galaxy m31 phone


Flutter or Kotlin for android?

Attainable Tech_sup

India Rocks Everywhere......
Especially in Coding???

Quick Sketch

Hi, i can' t access the link from the email


Mark Techson

Great video, folks! Looking forward to seeing it play out!

Paolo Cristofoli

It would be very nice to provide a full offline installation. People behind corporate proxy are having huge difficulties. #30daysOfFlutter


I missed the first session ?

Mukul Kumar

please open the registration plz plz plz

Janscob Tutorials

Please open the flutter registration again???? I have always wanted this, pls I don't want to miss this opportunity

Rasha Abdel Salam

i can't see good that dark background and small font.

دعاء عقل

i have registered but I don't get any notification for the rest of the course .

Priya Yelutla

In laptop command prompt showing error after passing flutter doctor any one please help me

Priyanka Khadse

has anyone received their mail for content resources and webinar links ?


I did not gey the schedule for rest of the classes except first class

Snehal Sha

Hot reload uyir

Haider Jaafer

Is it there a solution for ios build on windows machine when developing flutter

Chintan Patel

Is there any certificate for this course? If yes, then how to get it?

Shivani Nevgi

it's a great learning experience to learning flutter with google team, one step closer to Flutter. #30DaysOfFlutter

Anoop P A

Why are they not using the most used vscode here?!


1:50 hervorragend

Sv Mt

Please open the registration once again I want to do this course please

ramakrishna paidi

Great session of 30 Days of flutter & really happy to learning to #30DaysOfFlutter

Abdullah Hameed Fuleih


Alok Pratap Singh

I am so excited #30DayOfFlutter

Ahmd Asml

We need translation

Ali Sher Khan

All the sessions will be here on YouTube?

Nicolò Giuliani

When will subtitles be available?

معلومة - information

problem for me : i can't speak english . bon courage dans cette formation

Mr him dude

can God the 30 days program is going to be on youtube. i can't wait oh. am stuck at API. how to work with different API'S.

Anurag Tyagi

You guys are awesome ! Pls keep helping us poor students

Prateek A.

I loved this session. Scott had some really funny things to say.

Nuhla al-masri

Loved it

Sajas Mohammed

I really happy to learn the start of #30DaysOfFlutter journey.

Sampath Kumar S


Jenish Rudani - Projects

What are the expectations for flutter for embedded devices. Specifically, what are the limitations if any while interfacing with it devices.



Ajith Memana

The guy on the bottom looks like Aamir Khan :D

abelardo jaimes londoño

Soy novato pero aprendo rapido, espero me adopten en su comunidad y poder recibir de su apoyo, Familia Jaimes Munera COLOMBIA GRACIAS

Naincy Sharma

Great session


please am facing a problem when installing flutter. #30 days of flutter, Error: Error when reading '/C:/flutter/packages/flutter_tools/.packages': The system cannot find the file specified.

Mehmet Ali Kahil

Nilay yener :))

Saikat Paul


mr kumar

You guys can make a well planned brief video instead of streaming live. That would be more time saving and interesting. Hope you will consider this suggestion.

Farah Adel

Hello, will you provide subtitles in arabic to your videos? #30DaysOFlutter

Ken Yup

I always appreciate google,they’ve done a good job,and saved my money as well,cuz I no more necessary to watch else tutorials for flutter,love from China

Joseph Diaw

hello do you know any francophone platforms that follow the challenge and that will be useful to me
thank you

haizad jusoh

Great session

Abdullah Hameed Fuleih



Thank you for these sharing moments

Ankit Lakum

Place are provided

Kamran khan

Please make a playlist for #30daysflutter

Ahmd Asml

We need translation

Aadarsh Lokhande


Vikash kumar Upadhyay

Please tell us setup for VSCODE

Abeed Jan

Is there a discord for beginners?

Raja kumar

Thanks Google

fetian ans

I want a friend to remind you to follow a course and discuss it

Chris Osorio

Saludos desde Ecuador.. !! America .. Contento de estar aqui..

Kevin knife

To the point, start From 54:00

Uday Chandra Mahato

Excited to learn Flutter#30DaysOfFlutter

Pro Flutter уроки на русском

awesome ???

Ruben Alvarez

I registered yesterday but I still haven't received my email to get all the content

Amrinder Kaur

"Registrations open" was a really big surprise , Thanks for that.

Naman jain

i am unable to use external packages like english_words in dartpad

Red Persimmon

Please make A Group on telegram

Alex Шкёпу

I'm Following Flutter!!!
End You!?)

Aadarsh Lokhande

1:38:45 That's what she said

shivam sharma

Me watching the whole live again It looks so easy ...Wow Simon has an exceptional way of teaching while he tries to give complete detail without error. #30daysofflutter


Can you implement the YouTube table of contents for future videos? Thank you ?

JavaScript Array Cardio Practice - Day 1 — #JavaScript30 4/30

JavaScript Array Cardio Practice - Day 1 — #JavaScript30 4/302 Jan. 2017
75 339
Wes BosSubscribe 438 721

Today we sweat! In order

Today we sweat! In order to do the rest of the JavaScript30 exercises, we need to get really good at working with Arrays in JavaScript. Grab all the exercises and code samples at https://JavaScript30.com

Comments (100)
Fibré P

arghhhh the audio compression really bugs me -- i -- i -- i can't breeeeeathe  ?

Raphael Guedj

Is someone can explain the .sort() method ? I don"t understand the return 1 and else -1 .

Henry Kirya

great, but you need to watch this in at least 720p HD, sorry non-broadband people

Jean-Francois Bouzereau

At 22:30. obj[item] = (obj[item]||0) + 1 would do the trick
Also the sort function needs not to return 1 or -1, but merely a positive or negative value so
( a , b ) =>. a.year - b.year. would be ok


Hey Wes, I really dont get this one in the reduce function (No. 8)
What does it make exactly?

isa moner


Quentin McKay

One small correction.
1. At 9:58, the first time around total is equal to the first element in the array, not undefined.
Great series!


You need a sports drink, bay-bay!!

Иван Курочкин

Love you Bos. You are the greatest teacher I've ever met. Truly. We appreciate your ability to spark the interest. Best regards!


Thanks for your work, Wes. I'm learning a lot.

Paul Maximus

is this still up to date stuff?

Lucas José

Thanks Wes

Rodrigo Reynaga

Thanks, man. Great job !!

isa moner



0:08 skip the intro

Connor Richmond-Clark

can someone explain to me why const can be used in the sort method, isn't is getting reassigned each time?

khanh chung

in sort() we can return a.year - b.year


can somebody explain me this code?

const data = ['car', 'car', 'truck', 'truck', 'bike', 'walk', 'car', 'van', 'bike', 'walk', 'car', 'van', 'car', 'truck'];
const transportation = data.reduce(function(obj, item) {
if (!obj[item]) {
obj[item] = 0;
return obj;
}, {});

Azaz Ali Haideri

how do u type emojis in code


console.table totally blew my mind


I think you tried explaining the problem more than you explained the actual method. I would focus on trying to explain the actual method rather than the problem

Sakhamen Mhlongo

const ordered = inventors.sort((a,b) => (a.year - b.year)) also works.

Mathias Jacobsen

Holy shit Wes you are on fire :D


Wes voice reminds me a little bit of Mortys voice from Rick and Morty.. like thats how would adult Morty sound like.. lil bit? anyone else? no?

john m

No one else noticed Black Elk was missing a comma the whole time?

rot rose

Your are Great and recommended by Steve Stiffith, most formidable javascript teacher. Thank you for doing all these for us.

Matheus Coelho

thanks Bos, you're the man!

kazim كاظم

This might sound dumb but why do you in the argument put "inventor" instead of 'inventors'

And in some of the functions you do stuff like this:
``` const yearsLived = inventors.sort(function(a, b) {
const lastGuy = a.passed - a.year;
const nextGuy = b.passed - b.year;
if(lastGuy > nextGuy){
return -1;
return 1
}) ```

I thought you have to loop through the array to be able to get every object within it.

Sam Deleon

For everyone saying he doesn't explain, yes he doesn't. Pause the video, go read about the method/function in the documentation, make stuff with what you have learned from it then start the video again, if you dont do this you wont learn. Also, shout-out to the Odin Project!


thanks a lot!

Follow Trend

So hot examples! Thanks, Wes Bos! ​? ✅

Lin Chen

This tutorial is so helpful! Especially the reduce part!! I didn't know that we could set the initial value to an empty object. Thanks again.

How To

You explain it as if we already know the stuff. The reduce one was confusing af.

Anna McDougall

Am I right in assuming that a lot of these variable names could be any value? (i.e. are we defining them as we use them?) Like, for example, we could have inventors.filter(person => (person.year >= 1500)) rather than 'inventor'. I only ask because I can't see 'inventor' defined anywhere and the code seems to work regardless of what I put in those brackets. Does JavaScript automatically assign each item in the array to that variable for the purpose of the function only?

Igor Kalmykov

How to connect this Wikipedia page to my project?

Caroline Ho

thanks for the great video(s)! the discovery of console.table made my day :D ???
but ... I get the result 861 instead of 523 for console.log(totalYears) with the reduce method using exactly the same function as yours. Don't know what happened .. ? and for the reduce method, I got the error message in my console:
index-START.html:100 Uncaught TypeError: Cannot read property 'car' of undefined
at index-START.html:100
at Array.reduce (<anonymous>)
at index-START.html:99

Ruddy Rivero Cabero

Thanks for the tutorial, i like when you use first function then when you make it arrow function, it makes it easy for beginners to follow and understand.

808HI Vibes

this is just what I needed! Your way of explaining these subjects is great!

Farrukh Atabekov

great video. but thos typos are annoying or is it only to me?

Sal the Sad manShark

I use arr.forEach more than all the other array methods combined


lmao, I need more than a sport drink Wes. I need an energy drink with cocaine and some nootropics.

Adrian Contee

As a side note about the solution to exercise #7, the people array is already alphabetized by last name. Wes should have really mixed it up to actually SEE the array get rearranged or asked for the array to be alphabetized by first name. Oh and btw since the array is all strings you can just do people.sort() without passing a callback function as the sort method will sort them for you automatically. But again the array is already initially sorted correctly DOH!

Mike Miguel

can anyone explain why at 10:00 when you have to add the '0' as the second param it only works then even though according to this documentation below it says the default value if not set is already '0'?:


I understand what the second param does, but I don't understand why in this challenge it is needed but in the very first example in the documentation above it is not needed, surely even if its an array ( as opposed to the object in this example) the first time round of anything without declaring that 'total' parameter will always be undefined?

Thanks in advance

Elizaveta Afanaseva

Where is this 0 in reduce() coming from?


For people who got a different value for number 4, he added more people into the exercise after the video, so your result should be larger

Fidget Spinner

This guy is brilliant, he is very talented but still feels how tough it is for beginners and showcases his coding for all levels. Doesn't give it the big I AM like a lot of programmers do but is humble and helpful to all. Bravo.

Kristiyan Krastev

Can somebody give me some info on the sort exercise 7, where he puts two variable names within square brackets ? I pretty much understood it, but some additional info won't hurt me.

Franco Viccia


Toufiq Islam

Hi, your tutorials are remarkable! I would like to make a suggestion.

Instead of calling sort on inventors directly, like inventors.sort(<insert_sorting_code> ) I think one should duplicate the original array using Spread Operator and then call sort on the duplicated array, like so:

const inventors_cust = [...inventors] ;
const ordered = inventors_cust.sort (<insert_sorting_code>)

this way the original array will NOT BE MUTATED .

Thanks and cheers eveyrone :)

isa moner


Tyler Hills

People is already sorted by last name. Even if they weren't, people.sort(); would return what you wanted without any other work.


Was i supposed to know what each method meant before starting this?

Leonel Gauna

For anyone wondering why the end result of the exercise 7 is the same as the original array, it's because there is a confusion in the variable names inside the comparator function:
const alpha = people.sort((personA, personB) => {
const [lastA, firstA] = personA.split(', ');
const [lastB, firstB] = personB.split(', ');
return lastA > lastB ? 1 : -1; // We are comparing the FIRSTNAMES.

// lastA = person A FIRSTNAME ; firstA = person A LASTNAME <-- Wrong
// lastB = person B FIRSTNAME ; firstB = person B LASTNAME <-- Wrong

 console.log(lastA, firstA) // logs a person's FIRSTNAME and then LASTNAME.
As you see, the name of the variables are wrong, when doing "return lastA > lastB ? 1 : -1;" we are actually comparing the firstnames and if you look at the array, every first name starts with a "b", so alpha ends up being the same array as the original.
To fix this, just switch the names of the variables:
const alpha = people.sort((personA, personB) => {
const [firstA, lastA] = personA.split(', ');
const [firstB, lastB] = personB.split(', ');
return lastA > lastB ? 1 : -1; // Now we are correctly comparing the last names.

// firstA = person A FIRSTNAME ; lastA = person A LASTNAME <-- Now ok
// firstB = person A FIRSTNAME ; lastB = person A LASTNAME <-- Now ok

 And that's all.

Duncan Alexander

For #7, it still works if you remove everything within the sort method.

Radu Mușat

Hi there, sort exercise 7 completely eludes me, don't understand anything, would anyone be nice enough to explain it step by step? the sort method is super confusing by itself..

Alex Zahrai

I keep getting 'undefined' when i try to console.table(fifteen) in the first step. This might be a super nooby question but can someone help me out, please?

Andrew Cichewicz

it unsettling to me that the array map function does not actually make a map, but instead performs an operation on each index and returns a new array.

Imran Shaikh

Great Wes :)

Asifuzzaman Bappy

@Wes Bos Greetings, why is it that if(!obj[item]) {obj[item] = 0; } else {obj[item]++;}return obj; does returns items with count 0 in it??!!

full snippet:

let transport = cars.reduce((obj, item) => {
if(!obj[item]) {
obj[item] = 0;
} else {

return obj;

why am i getting a list with 0 counts where as without using "else" block it works just fine!!! Can anyone help with this??

Thanks y'all :)

Chloe Mcholoe

Jeez I'm not gonna remember ANY of these lol

Gazi Salah Uddin

thank you..pls keep it up !

Dinesh Patil

Hands down one of the great teachers on JavaScript, now I understand why everybody I asked about who's course or material should I go for and everyone said 'Wes Bos'. Feeling lucky I found you and your courses.

Ryan Dalton

As a beginner, I really hope to be on your level one day. You look like a Dev God from where I am sitting right now lol.

The Logic

17:00 are names in people array firstName, lastName syntax or lastName, firstName ?


Thank you Wes for the console.table ?


7th exercise on sorting people names is incorrect. Despite the fact Wes tried to sort them by their first names, not last - it still didn't work. His final array has Ambrose in the middle, while it has to be the first one. Long story short it just didn't sort them. Here is a bit longer, but working way of sorting:

const sorted = people
.map(item => `${item.split(', ')[1]} ${item.split(', ')[0]}`) // reformatting them to first + last names
.sort() // sorting in alphabetical order, no need to specify arguments.
.map(item => `${item.split(' ')[1]}, ${item.split(' ')[0]}`); // reformatting back in 'last name, first name' format.

The Design Creative - Diane Laidlaw

you had me at console.table()


Nice exercises! I was trying my own solutions before following along with yours. The reduce exercise is ambiguous about what it is asking for, however. The file asks to "sum up the instances of each of these." It might be more clearly worded as "return an object containing a key for each kind of vehicle with a value corresponding to the number of occurrences"

fossegrim emacs and esoteric computing

Thanks for the tutorial! One thing I noticed was that the 7. exercise (19:39) could be solved more concisely by not splitting the names into first and last name and instead just compare full names. Seing as all of the names start with the last name this is sufficient. Here is my solution:

let alpha = people.sort((person1, person2) => person1 > person2 ? 1 : -1);

Wolf De Rechter

Well explained and great video, thank you!

Stevenson Nelson

Holy gold mine

Lena Ryan

"Bennington, Chester"
[starts crying]

Azrael 998

const inventors = [
{ first: "Albert", last: "Einstein", year: 1879, passed: 1955 },
{ first: "Isaac", last: "Newton", year: 1643, passed: 1727 },
{ first: "Galileo", last: "Galilei", year: 1564, passed: 1642 },
{ first: "Marie", last: "Curie", year: 1867, passed: 1934 },
{ first: "Johanne", last: "Keppler", year: 1571, passed: 1630 },
{ first: "Nicolous", last: "Corpenicus", year: 1473, passed: 1543},
{ first: "Max", last: "Planck", year: 1858, passed: 1947},

Nicholas Berube

.includes for the 6th exercise says .includes is not a function

How To

Sometimes it makes more sense to write it out:

const firstAndLastName = inventors.map((inventor) => {
return inventor.first + " " + inventor.last;

shortcuts can be bad and make things unclear.

isa moner


Mya Paquette

Quarantine learning! Yay? I want to leave my house already... lol.

sonotype - multimedia art and programming

SandBox: https://github.com/wesbos/JavaScript30

Perry Palmtree

Nice one

James Brooks

why is the result of my reduce function 861 and yours is 523

Nasser FN

I have a problem with part 6 is not running links! it says caught undefined...! does anyone know the solution to that?

ginner zapata

1) .filter(): 1:17
1.1) console.table(): 2:48
2) .map(): 3:55
3) .sort(): 5:16
4) .reduce(): 7:47

**Did this 'cause I come back constantly.

Prince zohaib

hey wes Bos Which IDE you are using how to customize like yours please tell thanks

Gia dụng tiện ích Noha

In sort by brithday we can even use this to shorter our code!
birthdaySort = inventors.sort((a, b) => {
return a.year - b.year;
Same as for sort by year lived:
const yearLive = inventors.sort((a, b) => {
return b.passed - b.year - (a.passed - a.year);

Nathan Cornwell

for sorting oldest to youngest you could just do this:

ordered = inventors.sort((a,b) => a.year - b.year;

works just the same.


I'm a little lost but fair enough

Karthick P

why we need to put 0 to get result for ordered?

Chloe Mcholoe

Damn javasript is so freaking weird all this things the stupid weird arrow function my head hurts lol..

Dan Build

This challenge is just what I have been looking for!


the inventors array has changed since the video was released. does that mean people have been rioting because there weren't enough girls in the list of inventors? O-M-G-!!!


Why was the array changed?

Mr Es

why is it that returning 1 or -1 get stuff ordered ??? is it common knowledge


i think 19:41 it is the same array as initial array .....problem is not solved there


18:06 reading the names made me laugh so much idk why xD

Ashish Kumar

The output is not alphabetically sorted as the naming is mistaken. It should be like this
const[aFirst, aLast] = lastOne.split(', ');
const[bFirst, bLast] = lastOne.split(', ');

now, It will work fine. Btw, thanks for such a comprehensive tutorial. You are simply best :-O

Mohamed tarek


Hassan Abdinur

CONSOLE.TABLE!!!! Thank god I've seen this!!


It should be Elk, Black in the original array, not Black, Elk.

Bob O'Toole

man.. just came back to this for review and that last one hit a new kinda way this time.. PSHH so helpful

Sara Vega

I LOOOOOVE seeing you tighten up/reduce the size of the code. That is so freaking helpful.

JavaScript || 30 Days of Web Development

JavaScript || 30 Days of Web Development10 Jan. 2021
Hex HybridsSubscribe 438 721

Register at:

Register at: https://skillenza.com/challenge/30daysofwebdev

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