Well, changing all the objects to numbers didn't fix it. So maybe it's not the strings that are the problem?
update: changing all the objects to strings fixed the error, so it seems the evaluator is not accepting numbers as objects? However I believe they must be.
No, I'm mistaken it's still producing an error.
https://www.w3schools.com/js/tryit.asp?filename=tryjs_array
`<!DOCTYPE html>
<html>
<body>
<h2>JavaScript Arrays</h2>
<p id="demo"></p>
<script>
const nums = [1, 2, 3];
document.getElementById("demo").innerHTML = nums;
</script>
</body>
</html>
`
This seems to be acceptable to w3c.