My category structure is as follows:

- Top Category
---- Sub Category 1
------- Sub Sub Category 1.1
------- Sub Sub Category 1.2
------- Sub Sub Category 1.3
---- Sub Category 2
------- Sub Sub Category 2.1
------- Sub Sub Category 2.2
------- Sub Sub Category 2.3

I'm on a post under 1.2 so it would be:

Top Category -> Sub Category 1 -> Sub Sub Category 1.2 -> Current Post

NB: In the post ONLY "Sub Category 1" and "Sub Sub Category 1.2" are selected as categories ("Top Category" is not checked).

Now, how do I get get the slug of the Top Category ("top-category"), navigating backward?

Thanks!

My category structure is as follows:

- Top Category
---- Sub Category 1
------- Sub Sub Category 1.1
------- Sub Sub Category 1.2
------- Sub Sub Category 1.3
---- Sub Category 2
------- Sub Sub Category 2.1
------- Sub Sub Category 2.2
------- Sub Sub Category 2.3

I'm on a post under 1.2 so it would be:

Top Category -> Sub Category 1 -> Sub Sub Category 1.2 -> Current Post

NB: In the post ONLY "Sub Category 1" and "Sub Sub Category 1.2" are selected as categories ("Top Category" is not checked).

Now, how do I get get the slug of the Top Category ("top-category"), navigating backward?

Thanks!

• categories

2 Answers 2

get_ancestors() returns an array containing the parents of any given object.

This example has two categories. The parent with the id of 447 and the child with a id of 448 and returns the a category hierarchy (with IDs):

get_ancestors( 448, 'category' ); 

returns:

Array
(
    [0] => 447
) 

get_ancestors Codex Page

get_ancestors()

Is the correct way to get all the parent categories of a specific category in the hierarchical order, so to get the highest level parent you could extract the last item of the array returned like this:

// getting all the ancestors of the categories 
$ancestor_cat_ids = get_ancestors( $queried_cat_id, 'category');

// getting the last item of the array of ids returned by the get_ancestors() function
$highest_ancestor = $ancestor_cat_ids[count($ancestor_cat_ids) - 1];