Create dynamic HTML ID based off wordpress query - php

Question

I was wondering how I can create a dynamic set of IDs based off the amount of custom posts that are queried for the given post.
I'm using the Advance Custom Fields plugin and then I"m querying the custom fields in the given post. If you take a look below you'll see I have my custom fields being queried each one is wrapped in a div with an id "section-1". What I need is for the "section-1" to update to "section-3", "section-4" each time a new field name is queried. So if 5 fields are queried they each have their own ID.
<?php
// check if the repeater field has rows of data
if( have_rows('repeater_field_name') ):
// loop through the rows of data
while ( have_rows('repeater_field_name') ) : the_row();
// display a sub field value
<div id="section-1">
the_sub_field('sub_field_name');
</div>
endwhile;
else :
// no rows found
endif;
?>

Answer 1

Just set an index variable before the loop and increment it at each iteration. Use that inside your id.
<?php
$index = 1;
while ( have_rows('repeater_field_name') ) : the_row(); ?>
<div id="section-<?= $index; ?>">
<?php the_sub_field('sub_field_name'); ?>
</div>
<?php $index++
endwhile; ?>

Answer 2

Try this
<?php
// check if the repeater field has rows of data
if( have_rows('repeater_field_name') ):
$i = 0;
// loop through the rows of data
while ( have_rows('repeater_field_name') ) : the_row();
// display a sub field value
<div id="section-<?php echo ++$i; ?>">
the_sub_field('sub_field_name');
</div>
endwhile;
else :
// no rows found
endif;
?>