WordPress Custom Taxonomy Terms as Post Title Prefix

<?php
/*  WORDPRESS: Add prefix to post title in a page template, using one or more custom taxonomy terms.

    CASE: Website has a custom post type called 'Events' and a custom taxonomy called 'Nights'
    that behaves like post categories (hierarchical). New 'Nights' were added in order, starting
    with 'Monday' and ending with 'Sunday', so that term_id could be used for sorting. When 'Events'
    are created, one or more 'Nights' can be selected. This code adds a prefix to the event title.

    EXAMPLE: If event title is 'College Night' and 'Thursday' is selected, event title becomes
    'Thursday: College Night'

    PUNCTUATION: If multiple nights are selected, they get separated by commas and/or an ampersand.

    EXAMPLE: 'Thursday & Friday: College Night' -OR- 'Thursday, Friday & Saturday: College Night'
*/
    // Get the 'nights' custom taxonomy terms object for the current post
    $terms = get_the_terms( $post->ID, 'nights' );
    // Only create a prefix if the current post has 'nights' associated with it
    if ( $terms && ! is_wp_error( $terms ) ){
        $nightname = array();
        $nightorder = array();
        foreach ( $terms as $term ) {
            // Store night names (e.g. 'Monday', 'Tuesday') in an array
            $nightname[] = $term->name;
            // Store night term IDs in array; assumes they were added in order
            $nightorder [] = $term->term_id;
        }
        // Combine night names and ids as key=>value pairs in an associative array
        $nights = array_combine( $nightname, $nightorder );
        // Sort the nights by numeric value (term ID)
        asort( $nights, SORT_NUMERIC );
        // Combine night names, adding punctuation
        $prefix = join( ' & ', array_keys( $nights ) ) . ': ';
        // Convert all but the last ampersand into a comma
        $prefix = preg_replace( '/ \&(?=.*\&)/', ', ', $prefix );
    }
    <a href="<?php the_permalink();?>" alt="link to <?php the_title(); ?>"><h2><?php echo $prefix; the_title();?></h2></a>
?>