get_categories() only returns categories in use
For this I suggest to use:
wp_list_categories( $args );
Further explanations about this function and how to use: http://codex.wordpress.org/Template_Tags/wp_list_categories
For this I suggest to use:
wp_list_categories( $args );
Further explanations about this function and how to use: http://codex.wordpress.org/Template_Tags/wp_list_categories