如何为链接的url设置if(）语句

如何为链接的url而不是当前页面设置if/else条件？

我在这个代码的第4行遇到问题：

$args = array( 'post_type' => 'studies', 'posts_per_page' => 4 );
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
**if(url=the page I want to link to)** 
echo '<a href="'.get_permalink().'">'.get_the_post_thumbnail( $post->ID, '180,180' ).'</a>';
else
echo '<a href="#self" class="anchor-hover">'.get_the_post_thumbnail( $post->ID, '180,180' ).'</a>';
endwhile;