JSFiddle - React, Tailwind, and code Playground
by Denis
HTML
<ul>
<li class="list"><span id="1">11111</span></li>
<li class="list"><span id="2">22222</span></li>
<li class="list"><span id="3">33333</span></li>
<li class="list"><span id="4">44444</span></li>
</ul>
<div id="res"></div>
JavaScript
$(".list").data({'title': 'blabla'});
var n = 0;
$('.list').each(function(){
if($(this).data('title') == 'blabla'){
n++;
}
});
$('#res').text('Объектов со значением "blabla": ' + n);