Use jQuery ID Selector with CSS

Question

I'm actually creating a list with streamers and checking if they're online, if so they'll get a green background color.

Now I want to create an additional list next to my "team list" which includes every streamer.

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For this I'm trying to use the same method like the one I'm using for the background color.

$(".".concat(user)).css("background-color","lightgrey");

(to color every background color for the streamers)

But now I want to just hide the streamers in one list and not everywhere.

So I can't use this:

$(".".concat(user)).css("display", "none");

(would hide every offline streamer in every list)

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I already tried to apply the ID but actually I don't know how. If I use this:

$("#online".concat(user)).css("display", "none");

nothing happens.

(I named my ID online)

<tr class="header" id ="online">

(I already tried to apply the id to a new , to the and now to the but nothing works)

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TL;DR:

I want to hide offline streamers in a new list but I can't use the same ID selector as I used before. How can I do it?

Answer 1

Not much to start with, but if you have a structure like

    <table>
        <tr class="header Peter" id ="onlinePeter">
            <td>Peter</td>
        </tr>
        <tr class="header John" id ="onlineJohn">
            <td>John</td>
        </tr>
        <tr class="header Michael" id ="onlineMichael">
            <td>Michael</td>
        </tr>
        <tr class="header Bob" id ="onlineBob">
            <td>Bob</td>
        </tr>
        <tr class="header Daniel" id ="onlineDaniel">
            <td>Daniel</td>
        </tr>
    </table>

and a script like

var user = "John";
$("#online".concat(user)).css("display", "none");
user = "Daniel"
$(".".concat(user)).css("background","lightgrey");

It works. the row that contains John disappears

On the other piece of code where you try to change the background color, you are calling an element with the class = user, but the HTML you provided only has the class "header", once the class is added, the background changes as well.