Echo tag name if post has one of the tags

Question

I'm trying to echo one of the tags the posts has. There are multiple tags, around 40.

Currently I'm trying:

<?php
  $tag = get_tag(16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58);
  echo $tag->name;
?>

Edit:

function misha_filter_function(){


$args = array(
   'orderby' => 'date', // we will sort posts by date
   'order' => $_POST['date'] // ASC или DESC
  );


$args = array(
    'tax_query' => array(
      'relation' => 'AND',
      array(
        'taxonomy' => 'post_tag',
        'field' => $cat_id,
        'terms' => $_POST['locationfilter'],
      ),
    )
  );


$relation = 'AND';
    if( isset( $_POST['timefilter'] ) )
        $args['tax_query'] = array(
            'relation' => $relation,
            array(
                'taxonomy' => 'post_tag',
                'field' => $tag_id,
                'terms' => $_POST['timefilter']
            ),
        );

$query = new WP_Query( $args );

if( $query->have_posts() ) :
    while( $query->have_posts() ): $query->the_post(); ?>
<!-- post -->
<a href="<?php the_permalink()?>">
  <div class="col-md-3 col-sm-6 ver-item">
    <?php $thumb = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), 'full' );?>
    <div class="thumb" style="background-image:url('<?php echo $thumb['0'];?>');"></div>
    <section>
      <time>

        <!-- here is where the tag should be displayed -->
        <?php $post_tags = get_the_tags('YOUR POST ID');
        if ( $post_tags ) {
          echo $post_tags[0]->name;
        }?>
      </time>

      <h3><?php the_title();?></h3>
      <span><!-- underline --></span>
    </section>
  </div>
</a>

    <?php endwhile;
    wp_reset_postdata(); else :
    echo 'Geen resultaten, probeer het opnieuw.';
endif;
die();

But the problem with this is that it only outputs the first tag on all posts. That's the tag with the id 16. It even echo's the tag-id 16 to other posts, which don't even have that tag.

How can I echo only one the tags, if the posts has that tag/has one of those tag-ids?

Answer 1

Function get_tag retrieves post tag by tag ID or tag object.
This tags object is not connected with your current post.

Use get_the_tags to retrive tags of a current post in the loop

$post_tags = get_the_tags();
if ( $post_tags ) {
    echo $post_tags[0]->name; 
}

Add post id to get_the_tags function to retrieve tags of this post without loop

$post_tags = get_the_tags('YOUR POST ID');
if ( $post_tags ) {
    echo $post_tags[0]->name; 
}

Check if category exists in array of included tags using in_array

//outside the loop
$date_tags = array(16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58);

//inside the loop
//shows only first tag name if it finds one or more
$post_tags = get_the_tags();
if ( $post_tags && in_array($post_tags[0]->term_id, $date_tags ) ) {
    echo $post_tags[0]->name; 
}