How to assign a variable to an element in Javascript like in Actionscript?

In Actionscript I can do

var thing:MovieClip = new MovieClip ();
thing.somevar = 1;

and the thing object would have a variable calle开发者_如何转开发d somevar.

Can I do the same in Javascript if I created an element using createElement?

Yes, you'd be creating a custom/unsupported attribute for the HTML element that you can read back. Most people will say that it's not good practice but it does work on all browsers*.

Be careful though to avoid circular references. IE cannot free the memory used by objects with circular references if one of the object is an HTML element. This will result in memory leak on IE. Though other browsers can handle it well enough.

* At least all browsers I've ever tried.

Do you mean this?

var a = document.createElement("input");
alert(a.localName); // gets "input"