Should I place wp_reset_postdata(); after endwhile; or endif; ? - php

Question

I have spent some time reading through the WordPress Codex, as well as various themes, and can see that some developers insert <?php wp_reset_postdata(); ?> after the endif; in a Blog Loop whilst others insert the code between the endwhile; and endif; of a Blog Loop. I have tried both locations but have yet to see a difference. Is there a correct location?

Answer 1

This function supposed to reset the secondery query that you run.. the function the_postis letting you to use all the functions that you can run in the loop like the_title() the_content and so on..
So you reset the the_post function and after the endwhile; you can reset it already. and use your main query inside the if statment too if you like.
<?php
// this is the main query check if there is posts
if ( have_posts() ) :
// loop the main query post and run the_post() function on each post that you can use the function the_title() and so on..
while ( have_posts() ) : the_post();
the_title(); // title of the main query
// the is second query
$args = array( 'posts_per_page' => 3 );
$the_query = new WP_Query( $args );
// check if there is a posts in the second query
if ( $the_query->have_posts() ) :
// run the_post on the second query now you can use the functions..
while ( $the_query->have_posts() ) : $the_query->the_post();
the_title();
the_excerpt();
endwhile;
// reset the second query
wp_reset_postdata();
/* here we can use the main query function already if we want..
its in case that you want to do something only if the second query have posts.
You can run here third query too and so on...
*/
the_title(); // title of the main query for example
endif;
endwhile;
endif;
?>

Answer 2

wp_reset_postdata() is only required if you have a secondary loop (you're running additional queries on a page). The purpose of the function is to restore the global post variable back to the current post in the main query.
Example:
<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
OUTPUT MAIN POSTS HERE
<?php endwhile; endif; ?>
In the code above I'm simply using the main loop to display posts. There's no reason to include wp_reset_postdata(). The global post variable is exactly what it's supposed to be.
If somewhere else on the page I decide to add a secondary loop, then I'll need wp_reset_postdata().
// This query is just an example. It works but isn't particularly useful.
$secondary_query = new WP_Query( array(
'post_type' => 'page'
) );
if ( $secondary_query->have_posts() ) :
// Separating if and while to make answer clearer.
while ( $secondary_query->have_posts() ) : $secondary_query->the_post();
// OUTPUT MORE STUFF HERE.
endwhile;
wp_reset_postdata();
endif;
To answer your original question: it usually comes after endwhile and before endif. It's the call to the_post() which actually changes the global post variable. If there are no posts then the post variable remain the same and there's no reason to use the reset function.