show user id

// Add Shortcode
function custom_shortcode( $atts , $content = null ) {

	
	$user_id = get_current_user_id();
	if ($user_id == 0) {
	    echo 'You are currently not logged in.';
	} else {
	    echo 'You are logged in as user '.$user_id;
	}

}
add_shortcode( 'dataself', 'custom_shortcode' );