get current url drupal 8 code example

Example 1: Drupal 8 get page node current path

// Get current path.
$current_path = \Drupal::service('path.current')->getPath();
$path_alias = \Drupal::service('path.alias_manager')->getAliasByPath($current_path);

Example 2: drupal 8 get site base url

$host = \Drupal::request()->getSchemeAndHttpHost();