first-of-type selector
Description: Selects all elements that are the first among siblings of the same element name.
version added: 1.9jQuery( ":first-of-type" )
The :first-of-type selector matches elements that have no other element with both the same parent and the same element name coming before it in the document tree.
Example:
Find the first span in each matched div and add a class to it.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>first-of-type demo</title>
<style>
span.fot {
color: red;
font-size: 120%;
font-style: italic;
}
</style>
<script src="https://code.jquery.com/jquery-3.5.0.js"></script>
</head>
<body>
<div>
<span>Corey,</span>
<span>Yehuda,</span>
<span>Adam,</span>
<span>Todd</span>
</div>
<div>
<b>Nobody,</b>
<span>Jörn,</span>
<span>Scott,</span>
<span>Timo</span>
</div>
<script>
$( "span:first-of-type" ).addClass( "fot" );
</script>
</body>
</html>