Add a custom post class in WordPress

wpcustompostclass.php

<?php // First, create a custom field named 'custom_class' in WordPress and give it a value ?>


<?php	// The Loop...
	if (have_posts()) : ?>
	<?php while (have_posts()) : the_post(); ?>
		
		<?php 	// Declare a variable using the custom field
			$custom_classes = get_post_meta($post->ID, 'custom_class', false);  ?>

<?php // Use the variable in the post class ?>
<article <?php post_class($custom_classes) ?> id="post-<?php the_ID(); ?>">

This is the first time I've created a gist, so I hope I didn't do anything stupid.