functions used to get post content ,title ,image in wordpress through custom code code example

Example 1: wp+get feature image

<?php
	echo get_the_post_thumbnail( $post_id, 'thumbnail' );
?>

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>';
}