This function had been marked as deprecated since 2.1.0. Use wp_dropdown_categories()

Signature

dropdown_cats( $optionall = 1, $all = 'All', $orderby = 'ID', $order = 'asc', $show_last_update = 0, $show_count = 0, $hide_empty = 1, $optionnone = false, $selected = 0, $exclude = 0 )
optionall
 (int)
Default: 1
all
 (string)
Default: 'All'
orderby
 (string)
Default: 'ID'
order
 (string)
Default: 'asc'
show_last_update
 (int)
Default: 0
show_count
 (int)
Default: 0
hide_empty
 (int)
Default: 1
optionnone
 (boolean)
Default: false
selected
 (int)
Default: 0
exclude
 (int)
Default: 0

Return

(unknown)

Source

function dropdown_cats($optionall = 1, $all = 'All', $orderby = 'ID', $order = 'asc',
		$show_last_update = 0, $show_count = 0, $hide_empty = 1, $optionnone = false,
		$selected = 0, $exclude = 0) {
	_deprecated_function( __FUNCTION__, '2.1', 'wp_dropdown_categories()' );

	$show_option_all = '';
	if ( $optionall )
		$show_option_all = $all;

	$show_option_none = '';
	if ( $optionnone )
		$show_option_none = __('None');

	$vars = compact('show_option_all', 'show_option_none', 'orderby', 'order',
					'show_last_update', 'show_count', 'hide_empty', 'selected', 'exclude');
	$query = add_query_arg($vars, '');
	return wp_dropdown_categories($query);
}
WP Trac GitHub

Link here