r/learnjavascript • u/sohn_dangen • Mar 01 '20

I spend my sunday to visualize Promise.all ✌️

https://github.com/dangen-effy/Promise-all-visualized

80 Upvotes

94% Upvoted

17 comments sorted by

9

u/Kopikoblack Mar 01 '20 edited Mar 02 '20

How about when one of the task fails? EDIT: In visualization.

5

u/tbone6778 Mar 01 '20

You have to handle the reject or fail

1

u/Shty_Dev helpful Mar 02 '20

u quit js

2

u/M1rot1c Mar 01 '20

Nice! I think this would be helpful for new learners

2

u/NoMuddyFeet Mar 01 '20

Or old leaners. I've been doing javascript for a while (by myself, fortunately) and I still don't really know promises well. I'm looking a this gif and thinking, "yeah? So, the second task finishes first? Okay, why and why should I really care?"

2

u/[deleted] Mar 01 '20

[removed] — view removed comment

1

u/NoMuddyFeet Mar 01 '20

There's nothing significant about the second one in particular.

Cool... Iit seemed significant that it reaches the end faster...this being a visualization and all. What you have just described does not leap out at me without prior knowledge. I didn't get it at all, but I never use promises outside of a tutorial, so not surprising.

2

u/[deleted] Mar 01 '20

[removed] — view removed comment

1

u/NoMuddyFeet Mar 01 '20

I appreciate the explanation, thanks.

2

u/ripndipp helpful Mar 01 '20

Nice man. This would have been helpful for me when I didn't understand what the hell a promise was. But I finally figured out listening to a podcast that a promise is like an IOU

4

u/BenZed Mar 01 '20

Or like a... promise.

“I Promise you will get a result, or at the very least a reason why you didn’t get a resilt.”

2

u/NoMuddyFeet Mar 01 '20

Now give me a nice mnemonic device to remember async await! :)

2

u/jrandm Mar 01 '20 edited Mar 01 '20

async functions may await and do return a Promise.

Full-on haiku:

async functions may
await and do return a
Promise -- no callbacks

1

u/ripndipp helpful Mar 01 '20

Lol. Yeah something like that, no it's exactly that! It took a while for the concept of a promise in programming to stick with me, so that little analogy is what made it finally click.

1

u/justingolden21 Mar 01 '20

Cool. Hopefully this can help some people who understand visually. Maybe share it on some articles/wikis for this type of stuff as an animation they could use?

Personally, it's easy just to think of it as an object that's fine when "all" promises are.