Drupal 8 Get file system path or public directory path for drupal 8 instance.

The following code will return the root path for a drupal file system.

Sample code:

$path = \Drupal::service('file_system')->realpath(file_default_scheme() . "://") . '/');
print_r(“PATH : ”$path);

Output:

/var/www/html/directory_site_x/sites/default/files/