build_dropdown_script_block_core_categories example

$id                       = 'wp-block-categories-' . $block_id;
        $args['id']               = $id;
        $args['show_option_none'] = __( 'Select Category' );
        $wrapper_markup           = '<div %1$s><label class="screen-reader-text" for="' . esc_attr( $id ) . '">' . __( 'Categories' ) . '</label>%2$s</div>';
        $items_markup             = wp_dropdown_categories( $args );
        $type                     = 'dropdown';

        if ( ! is_admin() ) {
            // Inject the dropdown script immediately after the select dropdown.             $items_markup = preg_replace(
                '#(?<=</select>)#',
                build_dropdown_script_block_core_categories( $id ),
                $items_markup,
                1
            );
        }
    } else {
        $wrapper_markup = '<ul %1$s>%2$s</ul>';
        $items_markup   = wp_list_categories( $args );
        $type           = 'list';
    }

    $wrapper_attributes = get_block_wrapper_attributes( array( 'class' => "wp-block-categories-{$type}" ) );