how to get featured image in wordpress code example

Example 1: get featured image url

echo get_the_post_thumbnail_url();

Example 2: wordpress get fiture image

if ( has_post_thumbnail()) {
   $large_image_url = wp_get_attachment_image_src( get_post_thumbnail_id(), 'large');
   echo '<a href="' . $large_image_url[0] . '">';
   the_post_thumbnail('thumbnail');
   echo '</a>';
}