JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>
        <div class="wrap participantlist wrap_body" style="color:#000000">
            <input type="hidden" name="hidden" value="1" id="channel">
        </div>
    </li>
    <li>
        <div class="wrap participantlist wrap_body" style="color:#000000">
            <input type="hidden" name="hidden" value="2" id="channel">
        </div>
    </li>
    <li>
        <div class="wrap participantlist wrap_body" style="color:#000000">
            <input type="hidden" name="hidden" value="" id="channel">
        </div>
        </div>
    </li>
</ul>

JavaScript

var inc = 0;
$('input:hidden').each(function(){
    if ( this.value !== "" )
        inc++;
});
document.getElementById("resultado-count")

('input:hidden[value!=""]').length = ;