But this way is easier to reconcile the output, because the values logged shown are what they where at the time of the console.log(), not at the time of expansion (later).
Try this in a browser console: x={a:1,b:{c:1}};console.log(x);x.b.c=2;
then 'expand' the object, 'c' will be logged as 2, not 1
The original commenter was creating the object at log-time, though, which means it wouldn't be shared by anything else. Unless x or y is an object, but in that case the issue is completely tangential to the original suggestion
And anyway- JSON.parse(JSON.stringify(x)) would be preferable because you'd still get the browser's rich object exploration
