Count the number of widgets in a sidebar in WordPress

count_number_of_widgets_wordpress.php

<?php
/**
 * Count the number of widgets in a sidebar
 * Works for up to ten widgets
 * Usage <?php ctm_sidebar_class( 'promo' ); ?> where promo is the name of the sidebar
 */
function ctm_sidebar_class( $sidebar_name ) {
	global $sidebars_widgets;
	$count = count ($sidebars_widgets[$sidebar_name]);
	
	switch ( $count ) {
		case '1':
			$class = 'one';
			break;
		case '2':
			$class = 'two';
			break;
		case '3':
			$class = 'three';
			break;
		case '4':
			$class = 'four';
			break;
		case '5':
			$class = 'five';
			break;
		case '6':
			$class = 'six';
			break;
		case '7':
			$class = 'seven';
			break;
		case '8':
			$class = 'eight';
			break;
		case '9':
			$class = 'nine';
			break;
		case '10':
			$class = 'ten';
			break;
		default:
			$class = '';
			break;
	}

	if ( $class )
		echo 'class="' . $class . '"';
}