Question

Why is it that scripts can still function even after the code used to create them is removed from the DOM?

I ran into a situation where I wanted to prevent a broken script from running (@see my post).

In my attempt to come up with a solution I wrote an extension with the following line (just to see what would happen).

$('script', doc).remove();
/*doc is passed here because this script is running as a firefox extension 
  outside of the document context.*/

I assumed that this would remove all the scripts from the DOM, which it did, and that therefore no scripts would run on the page, which is not the case.

I would love to know more about what’s behind this behavior.

Answer 1

The script is part of the DOM, sure, but the result of that script executing is left up to the javascript engine. Removing a script’s source (the part that’s in the DOM) will not remove existing varibles in the engine’s memory.