Conditional testing for existence of an element

Question

I want to do this with jQuery

if $(".video-gallery-container") exists {
$(".video-gallery-container").fadeOut(300);
}

What's the proper way for checking for existence of an element with jQuery?

possible duplicate of [Is there an "exists" function for jQuery?](http://stackoverflow.com/questions/31044/is-there-an-exists-function-for-jquery) — Felix Kling, Jun 07 '13 at 11:18
You don't have to check whether element exists or not, jQuery doesn't throw error if element doesn't exists. — Ram, Jun 07 '13 at 11:20

score 3 · Accepted Answer · answered Jun 07 '13 at 11:19

3

jQuery provides the .length property for exactly this purpose:

if($(".video-gallery-container").length) {
    //.....
}

However, in your case you don't really need to worry about it: Just do the fadeOut without testing, because the fadeOut will only be applied to elements that match the selector; if there aren't any elements that match, the fadeOut won't be applied, but there won't be any errors.

answered Jun 07 '13 at 11:19

Spudley

166,037
39
233
307

Thank you, @Spudley – so, there's no need to do `.length>0` ? just `.length` is enough? – KeithRules Jun 07 '13 at 11:21
@KeithRules - just `.lenth` is sufficient because of the way javascript tests truthy values. But as I said, you don't even need to do that; the whole `if()` test isn't required at all in the example you've given. – Spudley Jun 07 '13 at 11:23

score 2 · Answer 2 · answered Jun 07 '13 at 11:19

2

You don't need to. If a selection is empty, any jQuery function called on it will simply fail to do anything:

$(".video-gallery-container").fadeOut(300);

That is all you need do.

answered Jun 07 '13 at 11:19

lonesomeday

233,373
50
316
318

What if I have it as a function: `$(".video-gallery-container").fadeOut(300, function() { // some code` - if there's bo video-gallery-container, I'm assuming it will prevent the inside code from being executed, no? – KeithRules Jun 07 '13 at 11:23
Yes. It's essentially a `for` loop. Think how many times `for (var i=0; i – lonesomeday Jun 07 '13 at 11:24

score 1 · Answer 3 · answered Jun 07 '13 at 11:18

1

if($(".video-gallery-container").length > 0){
  $(".video-gallery-container").fadeOut(300);
}

answered Jun 07 '13 at 11:18

Adil Shaikh

44,509
17
89
111

score 1 · Answer 4 · answered Jun 07 '13 at 11:19

1

if($(".video-gallery-container").length > 0){  
  $(".video-gallery-container").fadeOut(300); 
}

Also you need not check for existence. jQuery will only add fadeOut if the element exists, otherwise it will not do anything. no error will be produced.

answered Jun 07 '13 at 11:19

Nagarjun

2,346
19
28

Conditional testing for existence of an element

4 Answers4