Get a list of all WordPress categories as an array

get-wordpress-categories-array.php

/*
 * Get a list of all categories in WordPress and return them as an array.
 */
function getCategoriesArray() {

    // Retrieve object containing all of the categories.
    $cats = get_categories();

    // Convert the object into a simple array containing a list of categories.
    $categories[] =  '';
    foreach($cats as $category) {
        $categories[] = __( $category->cat_name, 'hs_textdomain' );
    }

    // Return the array.
    return $categories;
}