仔细查看blow代码-

$query_args = array(
    \'posts_per_page\'    => \'5\',
    \'orderby\'           => \'post_date\',
    \'order\'             => \'DESC\',
);

$listedPosts = new WP_Query($query_args);

// the loop
if ( $listedPosts->have_posts() ) {
    while ( $listedPosts->have_posts() ) {
        $listedPosts->the_post();
        if ( (int) $listedPosts->current_post == 5 ) { // You need to use \'==\' or \'===\' for comparison.
            // change the drop down field item to "Visible" from Invisible
        } else {
            // stay as is
        }
    }
}

$queried_object = get_queried_object();
$term_id = $queried_object->term_id;

For inside a loop-

//Do something if a specific array value exists within a post
$term_list = wp_get_post_terms(get_the_ID(), \'taxonomy _name\', array("fields" => "all"));
foreach($term_list as $term_single) {
    echo $term_single->slug; //do something here
}

For outside of the loop-

//Do something if a specific array value exists within a post
$term_list = wp_get_post_terms($post->ID, \'product_features\', array("fields" => "all"));
foreach($term_list as $term_single) {
    echo $term_single->slug; //do something here
}