:nth-child(2)
//https://www.sitepoint.com/comprehensive-jquery-selectors/
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>nth-child demo</title>
<style>
div {
float: left;
}
span {
color: blue;
}
</style>
<script src="https://code.jquery.com/jquery-3.5.0.js"></script>
</head>
<body>
<div>
<ul>
<li>John</li>
<li>Karl</li>
<li>Brandon</li>
</ul>
</div>
<div>
<ul>
<li>Sam</li>
</ul>
</div>
<div>
<ul>
<li>Glen</li>
<li>Tane</li>
<li>Ralph</li>
<li>David</li>
</ul>
</div>
<script>
/*This one is a bit complex.
It can accept a variety of values
as parameter like a number greater than or equal to 1,
the strings even and odd or an equation like 4n+1*/
$( "ul li:nth-child(2)" ).append( "<span> - 2nd!</span>" );
//karl - 2nd
//Tane - 2nd
</script>
</body>
</html>