Weird mapping of DOM elements into variables

Question

Today a workmate was working on a third-party video player integration for a set-top-box and found in their documentation an example like this:

<a id="say_hello">Hello</a>

<script type="text/javascript">
  say_hello.onclick = function() { alert("Hello world") }
</script>

I just suspected it was something related only with CE-HTML but tried it on Google Chrome and worked aswell.

Since when is it possible to access DOM elements this way?

Answer 1

Since at least Javascript 1.2, I believe. I've been using this kind of thing for about as long as I've been doing front-end programming.

Answer 2

Read the Shortcut Accessors section in this link: http://jibbering.com/faq/notes/form-access/. I think what you're accessing are the named properties. I even tried putting the <a> in a <div> but still I was able to access it using its name as above.