$user_id = 123; // Replace with an actual user ID if ( WP_User::get_data_by( 'ID', $user_id ) ) { // User exists } else { // User does not exist }
$username = 'johndoe'; // Replace with an actual username if ( username_exists( $username ) ) { // User exists } else { // User does not exist }
$email = 'johndoe@example.com'; // Replace with an actual email address if ( email_exists( $email ) ) { // User exists } else { // User does not exist }The `WP_User` class is a part of the WordPress Core package.