What are the drawbacks of accessing DOM elements directly by ID?

Question

Today I stumbled upon the possibility to access a DOM element in Javascript simply by its id e.g. like this:

elementid.style.backgroundColor = \"blue\"
         


        

Answer 1

You should also be concerned about name space. Right now you're treating it as if it's a variable in the global name space, and you would have to trust neither you nor any libraries that you include declare any global variables with the same name as DOM id's. The same goes for your highlight function.

Also while id's with dashes are perfectly valid, those would be inaccessible via this method.

e.g.

...

would become container-wrapper.style.color which would then try to subtract wrapper.style.color from container.