how to restart the apache server in ubuntu 18? code example

Example 1: ubuntu 14 apache2 graceful restart

# Restart Apache 2 server on Linux/Unix
sudo service apache2 restart

# Start Apache 2 server on Linux/Unix
sudo service apache2 start

# Stop Apache 2 server on Linux/Unix
sudo service apache2 stop

# Reload Apache 2 server on Linux/Unix "No downtime!"
sudo service apache2 reload

Example 2: stop apache server

# On Ubuntu
## Start command ##
systemctl start apache2.service
## Stop command ##
systemctl stop apache2.service
## Restart command ##
systemctl restart apache2.service