Answers for "error: apache shutdown unexpectedly."

Failed to start The Apache HTTP Server.

sudo systemctl status nginx
sudo systemctl stop nginx // if nginx is running

error: apache shutdown unexpectedly.

Follow the steps to solve your problem:
1_ open xammp
2_ click config in apache line
3_ click Apache(httpd.conf)
4_ search for '80'(Default Port) and change it to any number. ex: 81,82....
  change:
  1_ #Listen 12.34.56.78:80 to 81
  Listen 80 to 81
  2_ ServerName localhost:80 to 81
5_ save and exit.
** if your problem does not solved follow these steps**
1_ open xammp
2_ click config in apache line
3_ click Apache(httpd-ssl.conf)
4_ search for 443 and change it for 4433
  change:
  1_ Listen 443 to 4433
  2_ <VirtualHost _default_:443> to 4433
5_ save and exit.