Web code not working in code playground

Question

Why many web codes whichnuse Javascript, even the most popular one, are not working when I run them in he app code playground?
They end up with something like
requestAnimationFrame is not defined
Uncaught reference error: ... is not defined
illegal token on line...
illegal expression on line...
I don't know JS to try to fix it, but I found out that the keyword 'let' is one of thing which cause the problem

For example:

https://code.sololearn.com/Wofj3Kh7FvXN/?ref=app
https://code.sololearn.com/WqKUb6hN5A8j/?ref=app

Answer 1

Is it just the ES6 code that generates the error? If that is the case, I had exactly the same problem.I sent an email at [e-mail] and I got this as a reply:

You need to update your Android’s webview to the latest version, to support ES6 syntax.
You can get it from: https://play.google.com/store/apps/details?id=com.google.android.webview

Hope this helps!
If that's not the case, you can send an email to [e-mail] describing your problem.

Answer 2

michal You're welcome. As you say it is the keyword let that causes the problem, then your problem is probably the one I described above.

Answer 3

I'm not sure exactly what the problem is here, but I know there is often a delay in SoloLearn between loading the HTML and running the JS.

Try surrounding the entire JS code with this...

window.onload = function(){
//put the code here
};

Answer 4

James I got uncaught typeerror: onload property of object [object global] is not a function

Answer 5

Lucky Luke Thanks. It seems to be because of ES6 (but i don't know much about it so i'm not sure).

Answer 6

Oops. I fixed it. But I don't think it will fix the problem in this case.