# Sequencing Animations Assessment -- Prompt #1 question
**URL:** https://discourse.mozilla.org/t/sequencing-animations-assessment-prompt-1-question/96925
**Category:** Learn
**Tags:** learning
**Created:** [May 5, 2022, 11:47pm UTC](https://discourse.mozilla.org/t/sequencing-animations-assessment-prompt-1-question/96925 "2022-05-05T23:47:49Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@bdfee](https://discourse.mozilla.org/u/bdfee)
#### Post date: [May 5, 2022, 11:47pm UTC](https://discourse.mozilla.org/t/sequencing-animations-assessment-prompt-1-question/96925/1 "2022-05-05T23:47:49Z")
Hey y’all!
I have a solution to the prompt… but also a couple questions that I haven’t been able to confidently resolve.
In [prompt 1](https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Asynchronous/Sequencing_animations), we are asked the following:
> animate `alice2` when `alice1` has finished, and `alice3` when `alice2` has finished.
> Implement something that works, but has the promise version of the “callback hell” problem we saw in our [discussion of using callbacks](https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Asynchronous/Introducing#callbacks).
**a solution**
[a live solution is here](https://codepen.io/bdurf590/pen/abqvpKd)
**code in question from solution:**
```
alice1.animate(aliceTumbling, aliceTiming);
const promise1 = alice1.animate(aliceTumbling, aliceTiming).finished;
promise1.then(() => {
const promise2 = alice2.animate(aliceTumbling, aliceTiming).finished;
promise2.then(() => {
alice3.animate(aliceTumbling, aliceTiming)
});
});
```
**questions**
- Can the functionality of this code be accomplished using nested callbacks but _without_ the promise variables & `.then()`? (or setTimeout 🙂 )
- If not redundant to your first answer, what might have been an implementation for this (just generally speaking) that pre-dates promises?
hope this makes sense… many thanks for your time here and elsewhere on the forum!
---
### Author:  [@justsomeone](https://discourse.mozilla.org/u/justsomeone)
#### Post date: [May 7, 2022, 10:07am UTC](https://discourse.mozilla.org/t/sequencing-animations-assessment-prompt-1-question/96925/2 "2022-05-07T10:07:33Z")
Hello @bdfee
you doing great well done
by the way your email is displayed you can hide it from your profile page
> [@bdfee](#):
>
> Can the functionality of this code be accomplished using nested callbacks but _without_ the promise variables & `.then()` ? (or setTimeout 🙂 )
i am not sure of that cause how i know if the animate finish it’s work or if i did not used setTimeout based on my setting for the animations
let me ask @mikoMK and @schalkneethling if they have any way for that
and have a nice day all of you 🙂
---
### Author:  [@mikoMK](https://discourse.mozilla.org/u/mikoMK)
#### Post date: [May 8, 2022, 7:39am UTC](https://discourse.mozilla.org/t/sequencing-animations-assessment-prompt-1-question/96925/3 "2022-05-08T07:39:23Z")
Hi @bdfee
I’m not an expert on animations, but here are my thoughts.
I don’t think you can give a callback function to `animate()`. You could use the [`finish` event](https://developer.mozilla.org/en-US/docs/Web/API/Animation/finish_event) of an animation to then call the next animation from there. I think we agree that using the promise approach in this example is easier. 😁
Before the Web Animation API was created you would use [`setInterval()`](https://developer.mozilla.org/en-US/docs/Web/API/setInterval) to repeatedly call a function that manipulates the [`style` attribute](https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/style) of an element or adds/removes classes from the element. You could for example change the width of an element by setting different values to `elem.style.width` every call.
Later came the [`requestAnimationFrame()` function](https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame) to optimize the animation work of the browser while you still had to manually change the styles in the function.
I hope this gives you a little insight into this topic. 😃
Have a nice day,
Michael