jQuery - If DIV is present on page then add CSS to other DIV

Question

I'm very new to jQuery BUT I've got the basics down... At least I think I do? I'm just not sure how to put them together for them to actually work.

Example:
IF (div with ID of #dynamicChat) is present on the page. Then (div with class of .prdSection) height is 25px. Else do nothing

What I have so far:

$('#dynamicChat'){
$('.prdSection').css('height', '25px');
}

I don't think I'm far off... Saying that I probably am :) Any help would be great!

*Side question - If I'm referring to a Div on a page, what would I call it? An Element?

Thanks :)

you can always check the .length of a jq query to see if it is >0 — jumpdart, Mar 14 '14 at 19:48
possible duplicate of [Check if element exists in jQuery](http://stackoverflow.com/questions/4592493/check-if-element-exists-in-jquery) — aksu, Mar 14 '14 at 19:55

score 9 · Accepted Answer · answered Mar 14 '14 at 19:49

9

if ($('#dynamicChat').length > 0) {
    $('.prdSection').css('height', '25px');
}

answered Mar 14 '14 at 19:49

mathius1

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Fantastic! Thank you :) - Could you possibly explain what checking the length actually means / does? :) – Nick Mar 14 '14 at 19:52
length: "The number of elements in the jQuery object". http://api.jquery.com/length/ – mathius1 Mar 14 '14 at 20:10
length is needed, just not the > 0 :) – Chad Mar 14 '14 at 20:23

score 1 · Answer 2 · edited Nov 03 '15 at 10:54

1

You don’t need the “> 0”, you can simply write:

if ( $('#myElement').length ) {
// it exists
}

if ( $('#dynamicChat').length ) {
$('.prdSection').css('height', '25px');
}

edited Nov 03 '15 at 10:54

Aleksandr M

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answered Nov 03 '15 at 10:37

immazharkhan

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12

score 0 · Answer 3 · answered Mar 14 '14 at 19:52

0

No need of jQuery to check if that element exist :

if(document.getElementById('dynamicChat')){
    $('.prdSection').css('height', '25px');
}

answered Mar 14 '14 at 19:52

Karl-André Gagnon

33,662
5
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Ikbel · Answer 4 · 2022-06-01T12:25:58.653

0

If (div with ID of #dynamicChat) is present on the page. Then (div with class of .prdSection) height is 25px, else do nothing

   <script type="text/javascript">
        if ($('#dynamicChat').is("visible")) {
            $('.prdSection').css('height', '25px');
        }
    </script>

edited Jun 01 '22 at 12:25

answered Mar 11 '22 at 14:37

Ikbel

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1

Your answer could be improved by adding more information on what the code does and how it helps the OP. – Tyler2P Mar 12 '22 at 12:02

jQuery - If DIV is present on page then add CSS to other DIV

4 Answers4