WooCommerce: Get Top Level Category

Get the id of the top level category for a product no matter what it’s depth in the category tree.

• WooCommerce

function get_product_top_level_category ( $product_id ) {
 
        $product_terms            =  get_the_terms ( $product_id, 'product_cat' );
        $product_category         =  $product_terms[0]->parent;
        $product_category_term    =  get_term ( $product_category, 'product_cat' );
        $product_category_parent  =  $product_category_term->parent;
        $product_top_category     =  $product_category_term->term_id;
 
        while ( $product_category_parent  !=  0 ) {
                $product_category_term    =  get_term ( $product_category_parent, 'product_cat' );
                $product_category_parent  =  $product_category_term->parent;
                $product_top_category     =  $product_category_term->term_id;
        }
 
        return $product_top_category;
}

I tried a multitude of different built in WordPress and WooCommerce functions to get me to the top, but none of them actually did what I needed it to do which was return the id of the top-level category that a product might live in.

I needed this to work for any depth of categories, and a HUGE dependency is that it’s written to view the first category comes out of the get_the_terms call.