Variable width on posts using post count - wordpress

Question

I'm setting up a loop and with help from the $count I want to have different classes to the posts.
However, I want the $count to be dynamic, now I have to manually state the class depending on if the post count is equal to a number or not, as you can see in the code below.
$args = array(
'post_type' => 'post',
'posts_per_page' => -1
);
$loop = new WP_query( $args );
$count = 0;
while ( $loop->have_posts() ) : $loop->the_post();
$count++;
if( $count == 1) {
get_template_part( 'parts/case/item','six');
} elseif ( $count == 2) {
get_template_part( 'parts/case/item','three');
} elseif ( $count == 3) {
get_template_part( 'parts/case/item','three');
} elseif ( $count == 4) {
get_template_part( 'parts/case/item', 'six');
} elseif ( $count == 5) {
get_template_part( 'parts/case/item', 'six');
} elseif ( $count == 6) {
get_template_part( 'parts/case/item', 'three');
} else {
get_template_part( 'parts/case/item', 'three');
}
?>
<?php endwhile; wp_reset_postdata();?>
The number six and three are the classes of the posts.
What I want to execute.
Post 1 = class 6
Post 2 = class 3
Post 3 = class 3
Post 4 = class 6
Post 5 = class 6
Post 6 = class 3
Post 7 = class 3
Post 8 = class 6
Post 9 = class 6
And so forth.
Maybe, I'm looking at it the wrong way, the $count might not even be the way to go.
Appreciate all help.
Thank you.

Answer 1

You can try like this, without comparing each count individually.
if( $count == 1 || $count == 4 || $count == 5) {
get_template_part( 'parts/case/item','six');
} else {
get_template_part( 'parts/case/item', 'three');
}
Or you can even try like this
<?php
$args = array(
'post_type' => 'post',
'posts_per_page' => -1
);
$loop = new WP_query( $args );
$count = 0;
while ( $loop->have_posts() ) : $loop->the_post();
$count++;
get_template_part( 'parts/case/item', 'somecontentpart');
?>
<?php endwhile; wp_reset_postdata();?>
then in template part's class add following code
class="<?php echo ( $count == 1 || $count == 4 || $count == 5) ? 'class6' : 'class3';?>"