ACF Single relationship link showing up as an array?

I’m using ACF with flexible content and within that a relationship field to display a single link on the logo. I’ve set the maximum links to one, so don’t need a loop to display multiple links, I just need the URL for one relationship link.

$clnk is the link and it needs to be displayed within the href tag, i.e.

<a href="' . $clnk . '"><img class="client_logos" src="' . $cl . '" alt="" /></a>

But the link itself is coming up as /Array ?

Any help would be appreciated.

<h2>Our clients</h2>

<div class="services_container" style="display: block;">

    <?php
    // check if the flexible content field has rows of data
    if (have_rows('clients')):

    // loop through the rows of data
    while (have_rows('clients')) : the_row();

        if (get_row_layout() == 'clients'):
            $tl = get_sub_field('client_group_name');

            echo '<h2>' . $tl . '</h2>';

        endif;

    // Check rows repeater
    echo '<div class="clients_container">';

    if( have_rows('client_details') ):

        // Loop through rows.
        while( have_rows('client_details') ) : the_row();

            // Load sub field value.
            $cl = get_sub_field('client_logo');
            $cn = get_sub_field('client_name');
            $clnk = get_sub_field('client_link');
            
            echo '<a href="' . $clnk . '"><img class="client_logos" src="' . $cl . '" alt="" /></a>';

        // End loop.
        endwhile;

    endif;

    echo '</div>';

    endwhile;

    endif;
    ?>

</div><!--clients container-->

</div>

>Solution :

The official documentation for Relationship fields indicates that it will always return an array of the selected posts.

Adjusting your code to expect an array is simple enough (untested):

$clnks = ( array ) get_sub_field( 'client_link' );
$clnk  = array_pop( $clnks );

printf( '<a href="%s">', get_permalink( $clnk ) );

May want to consider changing the field type from Relationship to Link.