Add class to parent page and class to sub-child page

In WordPress, you can add a class to be applied anywhere in the web document, for example appending a class to the body tag, if the current page is a parent page or not.

Place the below if condition anywhere in your theme files; don’t insert it in functions.php

$current_page = get_page($post->ID);



if($current_page->post_parent > 0) {

    echo 'parent-page';

} else {

    echo 'no-parent-page';

}

?>

This will output parent-page on parent pages and no-parent-page on a sub-child page.