For Loops - Beau teaches JavaScript

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For loops are one of the most common ways to repeat things in JavaScript.
Code:
🔗 codepen.io/beaucarnes/pen/YZyW...
More info:
🔗 developer.mozilla.org/en-US/d...
Beau Carnes on Twitter: / carnesbeau
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Опубликовано:

12 мар 2017

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Комментарии : 85

@FreelanceFadi 4 года назад

The nested array part makes me wanna dropkick a toddler.

@YourBeautyRefinedAracely 3 года назад

LOL!!! this legit made me cackle. But I understand what u mean!

@EssLoco 3 года назад

I'm learning JS atm and nested for loops threw me off terriably, still got to push on i suppose

@grant2572 3 года назад

I needed this laugh while going through the same emotions lmao

@EssLoco 3 года назад

@@grant2572 i haven't laughed since learning about nested loops, unfortunately...

@grant2572 3 года назад

@@EssLoco - You on freecodecamp?

@oufcena5092 4 года назад

Loops are used to access arrays using the index of its elements. Nested arrays needs nested loops as a result. 1st loop to access the outer array & 2nd loop to access the inner one. var arr = [0, 2, [3, 2], 7]; arr[0] = 0; arr[1] = 2; arr[2] = [3, 2]; arr[2][0] = 3; arr[2][1] = 2; arr[3] = 7;

@godismyway7305 11 месяцев назад

Thank you so much!

@izaakchater9165 5 лет назад

Thank you very much for this. I was struggling to get a good understanding of this section in Code Academy but you've broken it down in a way that's given me a lightbulb moment

@bikepackingeurope2085 3 года назад

me too!

@ImParzelli 3 года назад

Coming from Codeacademy aswell haha One Year ago huh what's your progress now?

@godismyway7305 11 месяцев назад

@@ImParzelli What is n your progress brother?

@Mohammed-od4ju 3 года назад

Beau is a LEGEND in the dev game!

@Paltibenlaish 6 лет назад

always forget this for loop. thanks for the explanation!!!!! keep doing !

@nicolejsaunders 5 лет назад

Thank you so much! This one had my head spinning.

@fabriciohlgn6397 2 года назад

Thanks Beau, I needed a break; to fix my for loop… many thanks 😊

@Sage16226 5 лет назад

thanks for the easy explanation, just learning how to program, couldn't grasp the for loop until this video.

@temzeks 4 года назад

Any advances?

@cinammondream Год назад

What a beautiful thing to say! "Use your code for good!" WOW!!!

@veetoutas 6 лет назад

Thank You for sharing the knowledge. I really like Your videos, because You touch the topic a little bit deeper than just very very basics. I really start to understand stuff because of You. Your tutorials are highly appreciated. Liked and subscribed, my man.

@kandysman86 5 лет назад

It's been 11 months since this comment, how are you doing now?

@temzeks 4 года назад

Yeh id wanna know too

@haycheC 3 года назад

@@kandysman86 what about you? been 2 years?

@whyfoo Год назад

@@haycheC how about you its been 1 year ??

@jaycastaneda3318 Год назад

@waifutrades what about you? It's been half a year???

@janosvegh2510 4 года назад

Very good explanation, real teacher value here.

@ChrisTian-ox5nr 3 года назад

Thank You great tutorial on loops.

@MrWardo2009 3 года назад

Thanks! Great explanation!

@ciceroaraujo5183 4 года назад

Excellent professor

@ninastech777 11 месяцев назад

Thanks for explain!

@Hellokittyenby 5 лет назад

I didn’t understand 😭💔

@alicenikuze231 5 лет назад

Im also struggling to understand but i get the idea.

@alejandrocano88 4 года назад

keep on practicing, but i guess by this time you should already know ;)

@temzeks 4 года назад

Did you guys understand

@benjameerave4329 3 года назад

its just like while loops

@goldensleeves 3 года назад

Great video! It's very confusing how i++ happens AFTER each loop but it's placed at the beginning. Your video helped me see that was true. Thank you

@TheHappyKamper 3 года назад

yeah I think while loops are so much easier to understand visually. Using a while loop, the example in the video would look like this: while(i

@josh__f Год назад

Thanks, Beau!

@danielstoicamusic 6 лет назад

About the first example, why would you add an if statement which is totally opposite of the initial condition? Why not just say from the beginnin i

@joxim697 6 лет назад

From my point of view, he just used current example to explain how break works.

@neenus 6 лет назад

Great explanation thank you ... can I just ask is that jsfiddle that you are using?? if yes how did you show the console?? I'm new to all of this and I'm trying to do this so I can test my javascript while learning but I can't figure out how to show the console ... so far I've been using the console in developer tools in Chrome

@neenus 6 лет назад

never mind I just noticed your link to codepen but thanks anyway! that works as well.

@DrBotnus 3 года назад

console.log(Whatever you are logging in the console, for example calling a function and getting the outputs of it.);

@djhonz45 5 лет назад

Thank you!!!!

@Urmomsstockings Год назад

I am confused just because I feel like the first for loop for variable i could be sufficient to display the whole array. Is there a reason there is a second for loop?

@vmax924 7 лет назад

Thanks Beau, awesome tutorial! Just 1 question: I don't understand the output flow of 'console.log(arr[ i ] [ j ])'. I tried to output the log of 'console.log(arr[ j ])', the result was like : (2) [1, 2] (2) [3, 4] (2) [1, 2] (2) [3, 4] (2) [1, 2] (2) [3, 4] and also tried 'console.log(arr[ i ])', it was like: (2) [1, 2] (2) [1, 2] (2) [3, 4] (2) [3, 4] (2) [5, 6] (2) [5, 6] why does it always output 6 times? why on the first example, the loop didn't find the array [5,6]? Thanks for your great tutorial again!

@souravsuman1993 6 лет назад

I first part arr[j] the value of j was never 2 that' is why the it doesn't print [5,6] The six times printing on console was because your for loop goes 3*2 times

@eklavyasharma 4 года назад

My output seems to be overlapping while debugging in Chrome Browser Dev tool. I found the bug when I used the tab '\t' between nested loop. Anyone has idea why the chrome is behaving that way?

@cyrilmacauley9383 5 лет назад

nice.. which text editor are you using that comes with a console?

@zakiulhasan808 5 лет назад

I guess it's codepen.io

@JD-kf2ki 4 года назад

thanks dude

@Fishfood007 5 лет назад

What is the practical appilcation to this? I mostly get it and how it works wouldn't know what to do with it though...

@freecodecamp 5 лет назад

For loops are used all the time in programming. Here is one example: You may have an array of usernames. You could use a for loop to loop through the array and print every username to the screen in just a couple lines of code.

@debabratasen6955 5 лет назад

didn't understand that nested for loop

@orion.5611 3 года назад

what if the variable just holds one number?

@zachferell8359 4 года назад

how do you increment by two when looping thru an array?

@codynelson4 4 года назад

I believe you'd just do i + 2 instead of i++

@DrBotnus 3 года назад

for (let i=0; i < array.length; i+2)

@DrBotnus 3 года назад

or if you want to check all the adjacents, you could do for (let i=0; i < array.length; i++) { let up = array[i-4].something based of your code let left = array[i-1].something based of your code let right = array[i+1].something based of your code let down = array[i+4].something based of your code

@orion.5611 3 года назад

what if it is not an array?

@benjameerave4329 3 года назад

ok i understand but what to do with it?

@garrettbaker2320 6 лет назад

Does anyone ever give an example of for loops that actually ends up on a web page, and not just "console.log"? I'm at my wits end. "document.write" and "console.log" are of no use to me.

@danielstoicamusic 6 лет назад

No. :)

@geovaniraffaelli4508 6 лет назад

You can use it to loop through an array, so the instant someone writes something in a text box and submits it automatically goes to the array and back to the HTML, just like in a bookmarkers app or to-do list app. Dude I was struggling with this too but I didn't give up and eventually I understood it. Don't give up and sooner or later everything will click! Best wishes

@percyblakeney3743 6 лет назад

Nanika This comment wasn't directed at me but I'm going to pretend it was since it's sound advice I needed to hear (read) at this very moment. :)

@kandysman86 5 лет назад

@@percyblakeney3743 it's been 7 months, how are you doing now?

@percyblakeney3743 5 лет назад

@@kandysman86 I have a greater understanding now than I did 7 months ago. I even managed to finally obtain my javascript cert of completion from fcc, however I cannot stress enough the importance of persistence. To be honest I think I may give the course a second go in order to really drive it home. Thank you for asking and for reminding me to get back at it. How's your javascript knowledge?

@struestorystudios9225 5 лет назад

If i want to loop * how do i do?

@freecodecamp 5 лет назад

What do you mean when you say 'loop *'?

@jordan0076 3 года назад

Who ate my sandwich... MYYYYYYY SANDWICHHHHHH

@oamobile8415 2 года назад

Who new Ben Affleck was so good at JS!

@igotapochahontas 5 лет назад

That voice.....is that taco from the league? Or John lejoie from RU-vid?

@aaronargottelopez3488 4 года назад

@eumhiralejandrino885 5 лет назад

Grade 9?

@liuziyu4272 7 лет назад

the very last part I still can't understand it's so confusing

@liuziyu4272 7 лет назад

I don't understand the last part when I=0 j=0 it selects 1, but then doesn't I increased to 1 and it selects the second index which contains 3,4 shouldn't it display 1,3,5? I know the second loop continues if j is less than 2.

@liuziyu4272 7 лет назад

why does the second loop goes twice first?

@liuziyu4272 7 лет назад

is it because the second loop is nested inside the first loop?

@freecodecamp 7 лет назад

The second loop runs twice because of this part: "j < arr[i].length". arr[i].length equals two because there are two elements in the first nested array ([1, 2]). The first time the second loop runs, j = 0. The second time, j = 1. At the end of the second time, j is set to 2 so the loop stops since j is no longer less than 2.