With this way I only find the needed div, if the "data-content" contains the complete word.
var input = "TestText123";
var found = $("#list").find(".box[data-name='" + input + "']").addClass("found");
But I also want to find this div if my "input" just contains a correct part of it (min. 5 characters).
It's interesting, that this would work, if I don't use the "data" method (but I need it).
var found = $("#list").find(".box:contains('" + input + "')").addClass("found");
How to modify the "data" method in jQuery, like the way I need it?
Add an asterisk before the equal sign: [data-name*=...].
Side note: the argument of addClass should not have a dot, so just addClass("found"):
var input = "TestText123";
var found = $("#list").find(".box[data-name*='" + input + "']").addClass("found");.found { background: yellow }<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<ul id="list">
<li class ="box" data-name="WhatTestText12345">should match</li>
</ul>