如何将“else”添加到“foreach”？

i don't know how to add else to foreach!

here is my code:

<?php $terms = get_the_terms( $post->ID , 'actor' ); 
    foreach ( $terms as $term ) {
        $term_link = get_term_link( $term, 'actor' );
        if( is_wp_error( $term_link ) )
        continue;
        echo '<a href="' . $term_link . '">' . $term->name . '</a>';
    }
?>

You could try something similar:

<?php 
    $terms = get_the_terms( $post->ID , 'actor' ); 
    if ($terms) {
        foreach ( $terms as $term ) {
            $term_link = get_term_link( $term, 'actor' );
            if ( is_wp_error( $term_link ) )
                continue;
            echo '<a href="' . $term_link . '">' . $term->name . '</a>';
        }   
    } else {
        // do the work for else
    }
?>

foreach is a loop. else is part of a conditional statement. It looks like you just want a conditional inside your loop. This would just be a standard conditional.

if ($a > $b) {
  echo "a is greater than b";
} else {
  echo "a is NOT greater than b";
}

I assume you want to break the loop in that case.