I checked back discussions and I don't see this addressed. There's a
collision between Prototype and certain kinds of array calls as
documented at
http://zurahn.wordpress.com/2009/01/11/prototypejs-breaks-javascript-foreach-loops/
I saw this behavior on my site when I added an Amazon product
First of all, for..in is not the same as forEach.
In second place, iterating arrays with `for..in` is just stupid, it is meant
to be used with objects in general. It's well known that `for..in` is
extremely inefficient when compared to length-cached `for` loops.
So, you should be doing
var foo =
