WordPress shortcodes to show and hide text based on user authentication state

wordpress-functions.php

<?php 

if ( ! function_exists('show_logged_in_content')) {
    /**
     * Display text to logged in Donation users only
     * 
     * <code>
     * [loggedin]This content will only be displayed to logged in users.[/loggedin]
     * </code>
     * 
     * @author  Cosmo Mathieu <cosmo@cosmointeractive.co>
     * @link    http://acroweb.co.uk/user-logged-in-shortcode/
     * @param   $params
     * @param   $content
     * @return  string 
     */
    function show_logged_in_content ($params, $content = null){
        //check tha the user is logged in
        if ( is_user_logged_in() ){

            //user is logged in so show the content
            return $content;
        } else {

            //user is not logged in so hide the content
            return;
        }
    }
}
 
//add a shortcode which calls the above function
add_shortcode('loggedin', 'show_logged_in_content' );

if ( ! function_exists('show_logged_out_content')) {
    /**
     * Display text to logged out Donation users
     * 
     * <code>
     * [loggedout]This content will only be displayed to logged out users.[/loggedout]
     * </code>
     * 
     * @author  Cosmo Mathieu <cosmo@cosmointeractive.co>
     * @link    https://714web.com/wordpress-shortcode-to-show-or-hide-content/
     * @param   $params
     * @param   $content
     * @return  string 
     */
    function show_logged_out_content($params, $content = null) {
        if ( !is_user_logged_in() && !is_null( $content )) {
              return $content;
        } else {
            return '';
        }
    }
}
add_shortcode( 'loggedout', 'show_logged_out_content' );