(function() { document.getElementById() == null; })();

Question

Why self-executing anonymous function can't get access to DOM elements. Why such example does not work.

(function() {
    alert(document.getElementById('someElement'));
)();

Why alert will show "null"?

The function has nothing to do with it. The `getElemenById` call would return the same thing inside or outside of the function. — meager, Oct 06 '14 at 13:20
that's is my question, actually. Isn't that function supposed to be executed after DOM loaded? — Mark Zucchini, Oct 06 '14 at 13:20
@MarkZucchini: Exactly, hence you are confusing an IIFE with jQuery. — Felix Kling, Oct 06 '14 at 13:35

score 1 · Accepted Answer · answered Oct 06 '14 at 13:20

1

Just execute it on DOM load.You can use script defer attribute also.

(function() {
    window.addEventListener("load", function() {
        alert(document.getElementById('someElement'));
    }, false);
})();

answered Oct 06 '14 at 13:20

Georgi Naumov

3,890
4
33
50

1

maybe that's the way. thank you – Mark Zucchini Oct 06 '14 at 13:23

score 0 · Answer 2 · answered Oct 06 '14 at 13:27

0

Your missing your closing curly brace }.

It should be

(function() {
    alert(document.getElementById('someElement'));
})();

This will execute immediately so this needs to be placed somewhere appropriate to ensure the DOM has loaded. Make sure this script loads at the end of your HTML file, or include a check as Georgi Naumov has suggested, adding a listener to the window.load event will do the same thing.

answered Oct 06 '14 at 13:27

Mark Walters

10,729
6
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Thank you. Somehow I thought that this function executes after DOM loaded, not immediatelly – Mark Zucchini Oct 06 '14 at 13:29

(function() { document.getElementById() == null; })();

2 Answers2