entry1 entry2 entry3 şeklinde class isimleri oluşturmak istiyorum, bunu nasıl yapabilirim?

Örnek görsel:


Kodlar:

// The Loop
if ( $query2->have_posts() ) {
    while ( $query2->have_posts() ) {
        $query2->the_post();
        echo '<div class="entry">
            <a href="'; the_permalink(); echo '" title="'; the_title_attribute(); echo'">';
                echo '<span style="background-image: url('; echo the_post_thumbnail_url( 'featured-content-thumbnail' ); echo ')">';
            echo '</a>
            <h2>';
                the_title();
            echo'</h2>
        </div>';
    }
}

Dokuman: https://developer.wordpress.org/reference/classes/wp_query/