JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>http://www.youtube.com/watch?v=dw1Vh9Yzryo</li>
    <li>http://www.youtube.com/watch?v=bOF3o8B292U</li>
    <li>http://www.youtube.com/watch?v=yAY4vNJd7A8</li>
    <li>http://www.youtube.com/watch?v=yAY4vNJd7A8</li>
    <li>http://www.youtube.com/watch?v=dw1Vh9Yzryo</li>
    <li>http://www.youtube.com/watch?v=bOF3o8B292U</li>
    <li>http://www.youtube.com/watch?v=yAY4vNJd7A8</li>
    <li>http://www.youtube.com/watch?v=dw1Vh9Yzryo</li>
</ul>

JavaScript

var youtube = {};

function makeDLLink(video)
{
    return "*Download Link*";
}

$('li').each(function() {
    var videoLink = $(this).text();
    var download = makeDLLink(videoLink);
    if (!youtube[videoLink])
    {
        youtube[videoLink] = { "repeated": 1, "download": download };
    }
    else
    {
        youtube[videoLink].repeated += 1;
    }
});

$('ul').append("<br /><br /><br />");
for (var key in youtube)
{
    var obj = youtube[key];
    $('ul').append(key + " was repeated " + obj.repeated + " times and can be DL'd from " + obj.download + "<br /><br />");
}