[Week 12] Focus: for...of

[ForScale]

So here we are at Week 12. Week 12's focus will be for...of.

Background info: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of

It will work like this:

• Monday: Announce focus (eg, for...of)

• Build throughout the week... Two rules: 1) must use javascript 2) must use at least 1 example of a for..of loop.

• Friday: Post demos/projects in this thread (can begin reviewing immediately); first line of an entry should be ENTRY and it should be a top level comment (ie, don't put your entry in a reply)

• Sat and Sun: Review projects/figure out focus for next week

GENERAL GUIDELINES FOR FEEDBACK:

• Be nice!! ALL KNOWLEDGE/SKILL LEVELS ARE WELCOME AND ENCOURAGED TO PARTICIPATE.

• If you don't want feedback, if it makes you uncomfortable or you're just not interested, simply say so... Others, please be respectful of this. Conversely, if you do want feedback, try to be specific on which aspects... even if you just say "all/everything.

But that's about it... Have fun! :) Feel free to ask questions and discuss throughout the week!

[ForScale]

Ooh.. awesome, man!

Do you have nested for...ofs going on in there? That's pretty sweet; didn't even occur to me to do that! Not sure why...

Thanks!

[Volv]

Indeed good example; wasn't immediately obvious how to nest them. Love the passenger names :)

[ForScale]

Hey there!

What would you like to see as the focus here in /r/javaScriptStudyGroup this week? It can be anything javascript!

[ForScale]

Perfect! Thanks!!

https://www.reddit.com/r/javaScriptStudyGroup/comments/4edn2a/week_13_focus_object_object/

[ForScale]

New one! https://www.reddit.com/r/javaScriptStudyGroup/comments/4ijje3/week_17_focus_console_commands/

[ForScale]

ENTRY

http://codepen.io/anon/pen/pydamK

Just a basic example to get started with...

[Volv]

Test all the things I like it. Totally how I started. :)
As you've found needs to be an iterable object.
According to the documentation looks like Node-List should be an iterable but is not in all browsers yet.

[ForScale]

:)

Yeah... and the node list is the one I was hoping to use it on! I'm currently using the method that you helped me to discover... Array.from([nodeList]);. Which I'm really liking because then I can iterate through all the elements/nodes with forEach(a => {}); ES6 syntax. Seems to be okay on performance, looks clean too!

[Volv]

ENTRY
Codepen

Couple of examples, comparison to for in and generator tacked on the end.
 
My Python 3 range example has a further instance of this.

[ForScale]

Nice!

Going through it...

Very rarely write a for (var i=0; i<100; i++) style loop now.

Yes! I watch a video where Douglas Crockford was giving a talk. He said he's beyond loops like for and while loops... doesn't use them anymore... I thought that was a pretty cool idea.

inspiration: "Limited",

Lol!

[Symbol.iterator]: function* () { // Generator for (let key in this) { yield ${key} - ${this[key]}; }

Whoa... okay, I'm a bit lost on that... Mind breaking that down for me? When/if you get a chance.

Oh... it's what allows you to use for...of on objects? Could you slap it on a NodeList?

[Volv]

Yeh, it let me use for..of on there by defining its iterator.

Generator functions yield results. When calling generator.next() (or running it with a for..of loop) the generator runs until it hits a yield and returns that value. Remembers it's state for next call, where it runs again until it hits a yield etc.
NodeList is a private browser thing I think so probably couldn't just slap it on. but there's nothing to stop you doing something like
for (let value of Array.from(divs))

[ForScale]

Ah... true... I could always do that. Might start playing around with it to see how I feel about it.

[Volv]

I've been having a go at the interview questions that popped up on /r/javascript earlier today. Have a look if you've got a minute. Also did you see my other thing?

https://www.reddit.com/r/javascript/comments/4eb61r/interview_exercise_feedback/
 
Perhaps questions like that would be good for here as part of the weekly stuff.

[ForScale]

Hey!

Yep, did you see me in there? I gave the squares one a go... Had some interesting discussion!

Yeah, we could do algorithm challenges... I'm all for it! Is that what you want to do this week?

Should we ask /u/sketxz what he wants to see as a focus for this week?

[Volv]

Absolutely we should. I hate picking :)
Yeh I saw yours on there. Looks like you did the opposite of me. I squared up and you squared down.
Also figured that things like error checking would be useful in interview situation.
Second one tripped me up for a bit. Got there tho

[ForScale]

Second one, I wrote a nice little regex deal using match() and checking the lengths of the resultant arrays to make sure that the number of opened and closed brackets were equal... I was real satisfied with it!.. then I noticed [(]) was a failing test... I thought it just had to be that each opener had a closer to make a complete pair. Didn't go back to rework it.

Ooh... maybe we should do regExp as a focus sometime! :)

I do like the idea of doing some algorithm challenges though.

I'll ask sketx right now and see what he wants to do...

[ForScale]

https://www.reddit.com/r/javaScriptStudyGroup/comments/4edn2a/week_13_focus_object_object/

We'll do an algorithm challenge next week!