Question

Why do scripts still run after their tags get removed?

I was testing jQuery to remove style and link tags to remove CSS styles when i accidentally typed ‘script’ instead of ‘style’ for the selector. But what happened is that the scripts defined in those tags still run. Why is that?

here’s a sample in JS:

//assume foo is defined
foo();

var scripts = Array.prototype.slice.call(document.getElementsByTagName('script')),
    current;

//remove all scripts
while (scripts.length) {
    current = scripts.pop();
    current.parentNode.removeChild(current);
}

//foo still works
foo();​

same thing with jQuery:

foo();

$('script').remove();

foo();​

And a side question: If they don’t get removed this way, what will?

Answer 1

They run because they are loaded into memory when the script is first parsed.

You can set anything to undefined to disable it.