How to extract data out of a specific PHP array

Question

I have a multi-dimensional array that looks like this: The base array is indexed based on category ids from my catalog.

$cat[category_id]

Ea

Answer 1

function returnSortedParents($categories, $target_parent){

    $new_list = array();

    foreach($categories as $index => $array){
        //FIND ONLY THE ELEMENTS MATCHING THE TARGET PARENT ID 
        if($array['parent_category_id']==$target_parent){ 
            $new_list[$index = $array['sort_order'];
        }

    return asort($new_list);  //SORT BASED ON THE VALUES, WHICH IS THE SORTING ORDER
}