问题描述：

<?php
/*
Plugin Name: job list
Plugin URI: http://example.com/
Description: A complete and practical example of use of the Settings API. This plugin creates a new plugin administration page.
Author: WROX
Author URI: http://wrox.com
*/
function dwwp_register_taxonomy() {
$singular = \'Location\';
$plural = \'Locations\';
$slug = str_replace( \' \', \'_\', strtolower( $singular ) );
$labels = array(
\'name\'                       => $plural,
\'singular_name\'              => $singular,
\'search_items\'               => \'Search \' . $plural,
\'popular_items\'              => \'Popular \' . $plural,
\'all_items\'                  => \'All \' . $plural,
\'parent_item\'                => null,
\'parent_item_colon\'          => null,
\'edit_item\'                  => \'Edit \' . $singular,
\'update_item\'                => \'Update \' . $singular,
\'add_new_item\'               => \'Add New \' . $singular,
\'new_item_name\'              => \'New \' . $singular . \' Name\',
\'separate_items_with_commas\' => \'Separate \' . $plural . \' with commas\',
\'add_or_remove_items\'        => \'Add or remove \' . $plural,
\'choose_from_most_used\'      => \'Choose from the most used \' . $plural,
\'not_found\'                  => \'No \' . $plural . \' found.\',
\'menu_name\'                  => $plural,
);
$args = array(
\'hierarchical\'          => true,
\'labels\'                => $labels,
\'show_ui\'               => true,
\'show_admin_column\'     => true,
\'query_var\'             => true,
\'rewrite\'               => array( \'slug\' => $$slug ),
);
register_taxonomy( \'location\', $args );
}
add_action( \'init\', \'dwwp_register_taxonomy\' );

I creating wordpress plugin and i dont know taxonomy well it is giving me error

as follows..

Notice: Undefined variable: location in

C:\\XAMMP2\\htdocsateIt\\wp-content\\plugins\\job-listing.php on line 37

(this is line 37= register_taxonomy( \'location\', $args );)

网友观点：

register_taxonomy( \'location\', array(\'post type / custom post type\') $args );