for in / for of - Beau teaches JavaScript

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  • Опубліковано 16 січ 2025

КОМЕНТАРІ • 68

  • @lazarojoabe8939
    @lazarojoabe8939 2 роки тому +14

    MAAN! You helped me so much! in the first 10s you just explained a stuff I spent a few hours to know and couldn't. You're amazing!

  • @climbers1376
    @climbers1376 6 років тому +6

    "for in" loops through innumerable properties, property "names" 0:05:
    --1:58-2:16, object defined properties
    --3:12, array numeric indexes & object defined properties
    "for of" loops through iterable objects (i.e. array, map, set), property "values" 0:08:
    --4:01-4:18, values in arrays

    • @5tivi
      @5tivi 8 місяців тому

      very well put summary, but is it "innumerable" or "enumerable"? Those two words are antonyms

  • @ericzedd
    @ericzedd 4 роки тому +20

    Just remember!
    1. for (every prop in objects) { // do this } **objects - enumerable**
    2. for (every item of array) { // do this } **arrays - iterable***

    • @DannySi
      @DannySi 3 роки тому +3

      bruuuh this makes it so much easier to understand tyty

    • @vincentthamrin8252
      @vincentthamrin8252 2 роки тому +4

      bruh i watch the video im getting more confused and after reading this comment i starting to understand :v

    • @cannabisanomaly
      @cannabisanomaly 2 роки тому

      another helpful way to think about for...in when dealing with arrays:
      for...in looping will return the INdex of an array
      for...of looping will return the value OF an array

  • @studentcoder5840
    @studentcoder5840 6 років тому +12

    Wow, this is quite good! Though I think that instead of "x" the first variable name should've been "propertyName" -- just to make it more explicit and thus clear what's happening. And then maybe go over the code with "x" afterwards just to show that it really doesn't matter what that first variable is called.
    Slightly more problematically, in the beginning, stating that "'for...in' will loop through property names and 'for...of' will loop through property values" can be confusing at first when compared to the later statement (beginning at around 2:15) that the former works on what is enumerable while the latter what is iterable. In that vein, finally, I also thought that the later contrast between the two was good but felt just a bit rushed somehow.
    Still, overall a nice video for us beginners; thanks!

  • @blackpurple9163
    @blackpurple9163 2 роки тому +2

    This helped clear the difference between the 2 loops, thanks a lot

  • @khaledkharaz8037
    @khaledkharaz8037 7 років тому +42

    I was trying to understand this video i watched it many time but no point Then I decided to take break 30 min and come back to concentrate in last 10 video in this tuturiol and come back to this video just in one minute i find it very simple and clear new lesson today to take break after study couple of hour then come back will find everything easy, I love your video really very clear and important for everyone want to be perofessinal in JS Thank you bro

    • @BeauCarnes
      @BeauCarnes 7 років тому +9

      Same thing happens to me sometimes. Breaks can be really helpful!

    • @ReligionAndMaterialismDebunked
      @ReligionAndMaterialismDebunked Місяць тому

      Last ten, what? Seconds? This video is shorter than 10 minutes.

  • @90AlmostFamous
    @90AlmostFamous 7 років тому +5

    just remember by this:
    for (let index in Arr) {
    console.log(index + Arr[index] ); //gives fname beau
    }
    for (let item of Arr) {
    console.log(item); //gives 3,5,7
    }

  • @julioSWAC
    @julioSWAC Рік тому +1

    Thank you! had to watch it few times but you taught it VERY well. Kudos!

  • @mdrohimsikder7669
    @mdrohimsikder7669 6 років тому +18

    is it your actual typing speed? or editing?

    • @Qornv
      @Qornv 5 років тому

      editing

    • @drrragonfly
      @drrragonfly 5 років тому +7

      No, its fast forward, haven't you noticed the cursor blink?

  • @jackm1115
    @jackm1115 10 місяців тому +1

    Why use For Of loop when you could just use a traditional loop to get the job done? I'm guessing it costs less memory, but with this explanation For Of and traditional loops seems identical. Cheers :)

  • @fatemeetsluck
    @fatemeetsluck 4 роки тому +2

    This makes a lot of sense. I see how I need to restructure the semantics of my knockoff JavaScript interpreter.

  • @ll-sz9fl
    @ll-sz9fl 5 років тому +2

    Thank God you have two arms Beau!

  • @vijayrawat09
    @vijayrawat09 5 років тому +2

    Thanks for clearing my confusion between them :)

  • @davyjones6778
    @davyjones6778 4 роки тому +2

    Need to watch another video on "for..in" loops on the objects..

  • @nabsteve
    @nabsteve 3 роки тому

    Clearly and beautifully explained.
    Thanks a lot!

  • @mattmcgoo
    @mattmcgoo 2 роки тому +1

    Thanks Tom Green

  • @__jake.m
    @__jake.m 2 роки тому

    Thank you for this! You've clearly described the difference between the two! 💪🏽

  • @RurouniKenshinShinta
    @RurouniKenshinShinta 2 роки тому

    ty for explanation clear and to the point.

  • @KevinTempelx
    @KevinTempelx 4 роки тому +4

    To those who maybe are still confused I'm going to help you out and I'm going to be very specific with each individual word because they all mean something very important.
    ( let x in person ) - Also known as - ( Let X go into the variable person )
    1. (let) - tells x what to do
    2. (x)- is what will be going into something
    3. (In) - tells x to attach to the key properties inside the object
    4. (person) - is the destination for x

  • @sm1ley732
    @sm1ley732 5 років тому +3

    thanks but i have a question, in the end when you console log everything, why the for (of) loop didn't print the foo value ??

    • @Shad1991
      @Shad1991 4 роки тому +1

      Because the foo property is created as a key because arrays are actuallyobjects in js,...
      But the keys for arrays are indices therefore the value of the key foo cannot be added to the array....
      Note sure if I'm making sense to you..

    • @lizavetameta
      @lizavetameta 2 роки тому

      @@Shad1991 thank u! it really helps

  • @chestercopperpot8912
    @chestercopperpot8912 6 років тому +1

    your videos are helping me with the "WHY?" . thank you for these. :):)

  • @tomormiston6592
    @tomormiston6592 7 років тому +5

    one way of remembering : 'i' n --> ob 'j' ect [look visually similar]
    so the other must be : off --> array
    OR "I want to get to know you _in person_ " if you know that person is normally best as an object ?

    • @Qornv
      @Qornv 5 років тому

      yeah, very "intuitive" way

  • @supastar5702
    @supastar5702 2 роки тому +1

    Is he using code pen?

  • @mistermomo2904
    @mistermomo2904 4 роки тому +2

    yeah i did not understand shoit. Mainly cuz i have more of a problem understanding syntax. It's so helpful when code is turned into english text, then I get it mad quickk

  • @khalidelgazzar
    @khalidelgazzar 7 днів тому

    Great explanation
    Thank you

  • @seriouscapitalist
    @seriouscapitalist 7 років тому +3

    feels like javaScript god made these videos :D

  • @muhammadejaz5369
    @muhammadejaz5369 2 роки тому

    Thank you for this

  • @KgopotsoNtuli
    @KgopotsoNtuli Місяць тому +1

    Bro, you confused me even further🥲

  • @lyloft
    @lyloft 7 років тому

    why the `for of` can't output the `foo` value of the arr? It's confusing. Do you mind to explain that a little bit explicit? Many thanks.

    • @cheeseburger1884
      @cheeseburger1884 7 років тому +5

      'for of' only sees the iterable ""parts"" of an object, in this case [3,5,7] (an array, which is iterable).
      'for of' will ignore key:value pairs because they are not iterable.

    • @lyloft
      @lyloft 7 років тому

      Thanks, btw how can I know the pair is iterabal or not

    • @cheeseburger1884
      @cheeseburger1884 7 років тому

      you should google "javascript iterables". It gets pretty complex, I don't know it so I can't explain.

  • @hoanglam4964
    @hoanglam4964 5 років тому

    Please give me the application you used to write this

  • @daurham
    @daurham 4 роки тому +1

    I’m stuck on fitting a method inside a function. 😖 it sounds so simple!
    I can get it to run without being in a function (.split()) but the assignment is to create a function that splits a string of first + last name into an array of the split 2 strings.
    😫 this seems like it should be simple

  • @ousmand742
    @ousmand742 5 років тому

    is it possible to iterate through the values of the object with the for...in -- not using object.values ()

  • @kausarpial8062
    @kausarpial8062 6 років тому

    good explanation 👍

  • @pragyandas
    @pragyandas 7 років тому +1

    Your explanations are awesome! Just for the records...you are the usain bolt of typing

  • @RezaMohseni
    @RezaMohseni 4 роки тому +2

    Wonder if I can use this code for evil,,, hmmm

  • @phyapanchakpram
    @phyapanchakpram Рік тому

    Thank you

  • @hamidRaven13
    @hamidRaven13 2 роки тому

    tnx duuuude🙂

  • @lycan2494
    @lycan2494 5 років тому

    underrated

  • @RAYDENfilipp
    @RAYDENfilipp 7 років тому

    What is "let"??

    • @freecodecamp
      @freecodecamp  7 років тому +2

      Check out this video for an explanation of let: ua-cam.com/video/1mgLWu69ijU/v-deo.html

    • @RAYDENfilipp
      @RAYDENfilipp 7 років тому +2

      Great explanation. If I got it correct, in this case we can access "person" and "arr" let-type variables anywhere in the code, because they were declared in general scope? Am I right?

    • @BeauCarnes
      @BeauCarnes 7 років тому +2

      Yeah, that is right.

    • @lycan2494
      @lycan2494 5 років тому

      new version of var

  • @taihatranduc8613
    @taihatranduc8613 3 роки тому

    you are so good

  • @ApBananen
    @ApBananen 6 років тому

    perfect video :)

  • @mariachaudhry4608
    @mariachaudhry4608 5 років тому

    strange i have two arms too :o

  • @rockNbrain
    @rockNbrain 3 роки тому

    tks

  • @ВладимирОнуфрийчук-т4р

    Dude you're best, and bearded, HAHAHA

  • @hero_gaming08
    @hero_gaming08 2 роки тому

    kim bor

  • @sabertoothwallaby2937
    @sabertoothwallaby2937 4 роки тому

    Typical showing of your 2 arms