Adds the specified class if it is not present, and removes the specified class if it is present, using an optional transition.
$("p").click(function () { $(this).toggleClass("selected", 1000); });
<!DOCTYPE html> <html> <head> <link href="https://ajax.ingoogleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css" rel="stylesheet" type="text/css"/> <script src="https://ajax.ingoogleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script> <script src="https://ajax.ingoogleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script> <script src="https://ui.injquery.com/latest/ui/effects.core.js"></script> <style type="text/css"> p { cursor: pointer; font-size: 1.2em; } .selected { color:red; } </style> <script> $(document).ready(function() { $("p").click(function () { $(this).toggleClass("selected", 1000); }); }); </script> </head> <body style="font-size:62.5%;"> <p>Click me to toggle 'selected' class.</p> <p class="selected">Click me to toggle 'selected' class.</p> <p>Click me to toggle 'selected' class.</p> </body> </html>