Question

$cats=  get_categories(array(
    'order'                    => 'ASC',
    'orderby'                  => 'id',

    'hierarchical'             => 0,
    'hide_empty'               => 0,
    'taxonomy'                 => 'edu_year'
));

I would like to produce a variable that contains an array of the IDs of the values retrieved from the get_categories function.

Answer 1

Based on the documentation it returns:

$category->term_id
$category->name
$category->slug
$category->term_group
$category->term_taxonomy_id
$category->taxonomy
$category->description
$category->parent
$category->count
$category->cat_ID
$category->category_count
$category->category_description
$category->cat_name
$category->category_nicename
$category->category_parent

So:

$output_categories = array();
$categories=get_categories($args);
  foreach($categories as $category) { 
     $output_categories[$category->cat_ID] = $category->name;
}

Then $output_categories is exactly what you need.