How to pass current loop data into nested loop

Question

I have a custom post type (activities) and on each post I loop through another custom post type (tours).

In this second loop I want to create a variable containing the current post's name so I can use it to check if the tour contains the current page's activity.

I tried creating the variable before starting the second loop but it's lost and outputs nothing if I try to echo this in the second loop. This is probably obvious to most PHP and Wordpress developers so I'm sorry for my lack of knowledge here!

Here a simplified version of my code

<?php // start the activities loop ?>
<?php if (have_posts()) : while (have_posts()) : the_post(); ?>

    <?php // Get current post name ?>
    <?php $current_page = $post->post_name; ?>
    <?php $args = array(
        'post_type' => 'tours'
    );
    $tours_query = new WP_Query($args);
    ?>
    <?php if($tours_query->have_posts()): ?>                
        <?php while($tours_query->have_posts()): $tours_query->the_post(); ?>
            <?php the_title(); ?>
            <?php while(have_rows('itinerary')):the_row('itinerary'); ?>
                <?php $posts = get_sub_field('activity'); ?>
                <?php if($posts): ?>
                    <?php foreach( $posts as $post): // variable must be called $post (IMPORTANT) ?>
                        <?php setup_postdata($post); ?>
                        <?php // the permalink and title shown below are correct ?>
                        <a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>

                        <?php // Trying to get the current post name to use here ?>
                        <p>current post = <?php $current_page; ?></p>
                    <?php endforeach; ?>
                    <?php wp_reset_postdata(); // IMPORTANT - reset the $post object so the rest of the page works correctly ?>
                <?php else: ?>
                    <p>No activities found</p>
                <?php endif; ?>
            <?php endwhile; ?>
        <?php endwhile; ?>
    <?php wp_reset_postdata(); ?>
<?php endif; ?>

Thanks in advance for any help :)

Answer 1

What you've done with the variable is correct (defining it before starting the next loop), but you're not outputting it correctly:

<p>current post = <?php $current_page; ?></p>

If you want to output $current_page to the screen, you need to echo it:

<p>current post = <?php echo $current_page; ?></p>