<!DOCTYPE html> <html> <head> <title></title> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <script language="javascript" src="https://code.jquery.com/jquery-3.1.1.min.js"></script> <style type="text/css"> .active{ color:red; } </style> <script language="javascript"> $(document).ready(function(){ $('input').click(function(){ $('div p:first-child').addClass('active'); }); }); </script> </head> <body> <div> <span>Barcelona</span> <p>Manchester United</p> <p>Liverpool </p> <p>Paris Saint-Germain</p> <span>Real Madrid</span> </div> <div> <p>Chelsea</p> <p>Manchester City</p> <p>Juvetus</p> <p>Arsenal </p> <p>Bayern Munich</p> </div> <input type="button" value="Get first-child"/> </body> </html>