How to display categories of my Custom Post Type?

register_taxonomy('projects_cat', 'projects', array(
    'labels'    => array(
        'name'  => 'Category',
        'add_new_item'  => 'Add New Category',
        'parent_item'   => 'Parent Category',
    ),
    'public'        => true,
    'hierarchical'  => true
));



way one
===========================
<?php

$taxonomy = 'projects_cat';
$terms = get_terms($taxonomy); // Get all terms of a taxonomy

if ( $terms && !is_wp_error( $terms ) ) :
?>
    <ul>
        <?php foreach ( $terms as $term ) { ?>
            <li><a href="<?php echo get_term_link($term->slug, $taxonomy); ?>"><?php echo $term->name; ?></a></li>
        <?php } ?>
    </ul>
<?php endif;?>

?>









//create two taxonomies, genres and tags for the post type "tag"
===========================
        function create_tag_taxonomies() {
            // Add new taxonomy, NOT hierarchical (like tags)
            $labels = array(
                'name'          => _x( 'Tags', 'taxonomy general name' ),
                'singular_name' => _x( 'Tag', 'taxonomy singular name' ),
                'search_items'  =>  __( 'Search Tags' ),
                'popular_items' => __( 'Popular Tags' ),
                'all_items'     => __( 'All Tags' ),
                'parent_item'   => null,
                'parent_item_colon' => null,
                'edit_item'         => __( 'Edit Tag' ), 
                'update_item'       => __( 'Update Tag' ),
                'add_new_item'      => __( 'Add New Tag' ),
                'new_item_name'     => __( 'New Tag Name' ),
                'separate_items_with_commas' => __( 'Separate tags with commas' ),
                'add_or_remove_items'   => __( 'Add or remove tags' ),
                'choose_from_most_used' => __( 'Choose from the most used tags' ),
                'menu_name'             => __( 'Tags' ),
            ); 

            register_taxonomy('projects_tag','projects',array(
                'hierarchical'  => false,
                'labels'        => $labels,
                'show_ui'       => true,
                'update_count_callback' => '_update_post_term_count',
                'query_var'             => true,
                'rewrite'               => array( 'slug' => 'tag' ),
            ));
        }
        add_action( 'init', 'create_tag_taxonomies', 0 );



<?php

$terms = wp_get_post_terms($post->ID, 'projects_tag');
  if ($terms) {
      $output = array();
      foreach ($terms as $term) {
          $output[] = '<a>slug .'" href="' .get_term_link( $term->slug, 'projects_tag') .'">' .$term->name .'</a>';
      }
      echo join( ', ', $output );
  }
  ?>