The expression $(document).ready(function() deprecated in jQuery3.
See working fiddle with jQuery 3 here
Take into account I didn't include the showless button.
Here's the code:
JS
$(function () {
x=3;
$('#myList li').slice(0, 3).show();
$('#loadMore').on('click', function (e) {
e.preventDefault();
x = x+5;
$('#myList li').slice(0, x).slideDown();
});
});
CSS
#myList li{display:none;
}
#loadMore {
color:green;
cursor:pointer;
}
#loadMore:hover {
color:black;
}