How to Loop with the final result formatted differently?

Question

I need to list post_title's in this specific format (note the last title in the list must not have a comma)

    "post_title","post_title","post_title"

I thought a mini-loop might work. Here's what I'm using

            <?php query_posts('cat=0$posts_per_page=-1'); // query to show all posts independant from what is in the center;
                if (have_posts()) :
                    while (have_posts()) : the_post(); ?>
                        '<?php the_title(); ?>',
                    <?php endwhile; endif;
                wp_reset_query();
                ?>]">

But I need the final post_title to have no trailing comma?

Answer 1

I'm not sure of the context for this, but query_posts probably isn't what you want to use. (See this answer).

(Untested). I would use get_posts:

$posts = get_posts(array(
  'numberposts'=>-1,
  'category'=>0
 ));

And then use wp_list_pluck to get the titles:

$post_titles = wp_list_pluck($posts,'post_title');
$post_titles = array_map('esc_html',$post_titles);

Finally, the php implode function an list them with commas:

echo '"'.implode('","',$post_titles).'"';

Answer 2

change that line:

'<?php the_title(); ?>',

to:

<?php if( $wp_query->current_post ) { echo ', ';} ?>'<?php the_title(); ?>'