JSFiddle - React, Tailwind, and code Playground

HTML

<div class="a">http://www.youtube.com/watch?v=QkNrSpqUr-E</div>
<div class="a">http://www.youtube.com/watch?v=DABphlXEyW8</div>

JavaScript

$('.a').html(function(i,v){
    var id = v.split('watch?v=')[1]; // get the id so you can add to iframe
    return '<iframe width="150" height="150" src="http://www.youtube.com/embed/' + id + '" frameborder="0" allowfullscreen></iframe>';
});