List posts that don't have a specific tag?

Question

I am trying to list posts that do NOT have specific tags.

Currently, I am looping through each tag in a post, and if it's doesn't exist, list it. This works, except that it will list the same URL multiple times, if there are more than one tag.

<?php
// the query
$wpb_all_query = new WP_Query(array('post_type'=>'post', 'post_status'=>'publish', 'posts_per_page'=>-1)); ?>
<?php if ( $wpb_all_query->have_posts() ) : ?>
<ul>

    <!-- the loop -->
    <?php while ( $wpb_all_query->have_posts() ) : $wpb_all_query->the_post(); ?>
        <?php $post_tags = get_the_tags(); ?>
        <?php foreach ($post_tags as $tag) : ?>
            <?php if ($tag->name != "Tag1" and $tag->name != "Tag2" and $tag->name != "Tag3"): ?>
                <li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></li>
            <?php endif; ?>

       <?php endforeach; ?> 
       <?php endwhile; ?>
    <!-- end of the loop -->

</ul>
<?php wp_reset_postdata(); ?>
<?php endif; ?>

For instance, a post with tags Fun, and Learning will list twice in a row. I just want this listed once.

Is there a way I can quickly check all tags in a post instead of looping?

Edit: I tried adding all the tags to a string, and using strpos() but that seems to only check the first condition, and not the second/third:

<?php while ( $wpb_all_query->have_posts() ) : $wpb_all_query->the_post(); ?>
   <?php $alltags = ""; ?>
    <?php $post_tags = get_the_tags(); ?>
    <?php foreach ($post_tags as $tag) : ?>
     <?php $alltags .= $tag->name . " "; ?>
     <?php endforeach; ?>
      <?php if ((strpos($alltags, "SCA") == false) and (strpos($alltags, "SCAA") == false) and (strpos($alltags, "Tea and Coffee") == false)): ?>
    <li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a> - <?php echo $alltags; ?></li>
    <?php endif; ?>
   <?php endwhile; ?>

Answer 1

I believe you can filter them out in your original WP_Query using Taxonomy Parameters. Then you can delete the for loop altogether.

$args = array(
    'post_type' => 'post',
    'posts_per_page' =>-1,
    'tax_query' => array(
        array(
            'taxonomy' => 'post_tag',
            'field'    => 'slug',
            'terms'    => array('fun','learning'),
            'operator' => 'NOT IN',
        ),
    ),
);
$wpb_all_query = new WP_Query( $args );