In order to access a Garmin device from Javascript in a web page, the Prototype framework needs to be loaded. The bad thing about Prototype is that messes other things up. One nice thing about jQuery is that it is nonintrusive, defining only one global symbol. Prototype, on the other hand screws with basic Javascript datatypes.

The first thing that I had to deal with after loading Prototype was that I could no longer use for (i in array) { ... }, to iterate through array elements without getting a bunch of extra junk. So I rewrote my for loops to go from 0 to array.length - 1 instead.

The next thing really confused me for hours. I wanted to encode a Javascript data structure as JSON, and JSON.stringify([]) would inexplicably result in "\"[]\"". But if I used the browser's Javascript console, JSON.stringify([]) would correctly result in "[]". Finally, I came across a web page that identified Prototype as causing this problem by setting Array.prototype.toJSON, among other things, which also explained to me why Prototype was screwing up my for loops iterating through arrays.