Sencillo script que permite extraer categorias y subcategorias de wordpress a un array

get_array_categorys.php

<?php
 /**
  *@example $array_categorys = get_array_categorys();
  */
 function get_array_categorys()
{
    $categories = get_categories(array('type' => 'post','orderby' => 'name','order' => 'ASC','hide_empty' => false));
    $wp_cat = array();
        
    //Get categorys parents
    foreach($categories as $category){
        if($category->parent=="0" AND $category->slug != "uncategorized")
        {
            $wp_cat[$category->term_id] = array(
                                            "id"    => $category->term_id,
                                            "name"  => $category->name,
                                            "slug"  => $category->slug,
                                            "subcategorys" => array(),
                                        ); 
        }
    }

    //get subcategorys 
    foreach($categories as $category){
        if($category->parent!="0" AND $category->slug != "uncategorized")
        {
            $subcategory = array(
                                "id"    => $category->term_id,
                                "name"  => $category->name,
                                "slug"  => $category->slug,
                            );             
            array_push($wp_cat[$category->parent]["subcategorys"],$subcategory);                            
        }
    }
    return $wp_cat;
}