wp_list_categories() – Trying to get property of non-object

all results returned as i want only (even hidden) notice irritate me

How is the variable $category created? Can you post the output of var_dump( $category );?

source before

$category = get_category(18); // Industry’s Insights

var_dump($category);

object(stdClass)#1740 (16) {
["term_id"]=> &int(18)
["name"]=> &string(19) "Industry's Insights"
["slug"]=> &string(18) "industrys-insights"
["term_group"]=> int(0)
["term_taxonomy_id"]=> int(18)
["taxonomy"]=> string(8) "category"
["description"]=> &string(0) ""
["parent"]=> &int(0)
["count"]=> &int(78)
["filter"]=> string(3) "raw"
["cat_ID"]=> &int(18)
["category_count"]=> &int(78)
["category_description"]=> &string(0) ""
["cat_name"]=> &string(19) "Industry's Insights"
["category_nicename"]=> &string(18) "industrys-insights"
["category_parent"]=> &int(0)
}

in <b>mysite/wp-includes/category-template.php</b> on line <b>1025</b>

if ( !empty($current_category) ) {
	$_current_category = get_term( $current_category, $category->taxonomy );
	var_dump($_current_category); // !!!!!!!!

	if ( $category->term_id == $current_category )
		$class .=  ' current-cat';
	elseif ( $category->term_id == $_current_category->parent )
		$class .=  ' current-cat-parent';
	}

this dump

var_dump( $_current_category->parent );
show NULL

I’m sorry, but I can’t reproduce your error. When I use your code, I get a list of categories that are child categories of the listed category ID. In your last post, you posted a code snippet from WP core, and my copy doesn’t have the var_dump() line in it. Did you add that yourself? Which line is line 1025?

1025 line this:

elseif ( $category->term_id == $_current_category->parent )

also i already shown var_dump of $_current_category variable.
Thats mean – developers couldn’t consider NULL value for $_current_category.

By another words – current core sources must be like this

if ( $category->term_id == $current_category )
	$class .=  ' current-cat';
elseif ( isset($_current_category->parent) && $category->term_id == $_current_category->parent )
	$class .=  ' current-cat-parent';
}

or exists something else astral situation like moonlight in last spring week…

What are you trying to accomplish? I noticed that the category ID is 18, but you’re setting current_category to 1 in your call to wp_list_categories(). Also, I can reproduce your error if I set current_category to a number that doesn’t correspond to the ID of an existing category.

i want to understand whats source line call notices
so &current_category=1 is superfluous. Thats all. Thanks