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Comment by pavel_lishin | Hacker News Reader

Cute; I didn't realize that the element's ID implicitly mapped it to a javascript variable in Chrome.

It's an old browser feature. I think the idea was so you could easily reference other elements in inline-HTML event handlers (onclick= etc.).

Personally I find it handy for messing around in jsfiddle and the like:

    <pre id="out"></pre>

    [...]
    out.innerHTML += some_result;

Can anyone speak a bit more to that? I was wondering if this was just a convenience feature that browsers added or something that has been in Javascript all along?

Has been like this for as long as I can remember (at least back to IE6).

Yup - in fact there's an old bug that jQuery (in versions < 2, I believe) accounts for where IE would return elements with a name equal to the id you're searching for as the underlying system there was all wonky.

e.g:

    <input name="test">
    <div id="test">

    document.getElementById('test'); // <input> in IE6

I believe this also wound up in some Webkit and Opera releases, perhaps for emulation. Someone more knowledgeable about it all should feel free to correct me if I'm wrong though.