Apache VirtualHost configure - apache

Question

After I configured virtual host, my apache document root changed to the virtual host's document root, I just want to know why.
here is my httpd-vhosts.conf:
<VirtualHost *:80>
ServerName myapp.zend
DocumentRoot /opt/lampp/htdocs/php_zend_projects/myapp
<Directory /opt/lampp/htdocs/php_zend_projects/myapp/public>
DirectoryIndex index.php
AllowOverride All
Order allow,deny
Allow from all
<IfModule mod_authz_core.c>
Require all granted
</IfModule>
</Directory>
</VirtualHost>
After I restart apache server, localhost page changed to index of /opt/lampp/htdocs/php_zend_projects/myapp,
http://gwjyhs.com/t6/702/1556725814x2728329017.png
but it is supposed to be xampp's default page like this:
http://gwjyhs.com/t6/702/1556726269x2728278877.png

Answer 1

If you enable vhosts you have to add an entry that looks like:
<VirtualHost *:80>
DocumentRoot "F:/Dev/xampp/htdocs"
ServerName localhost
</VirtualHost>
Note: change path to whatever is appropriate for you.
Restart webserver and it should work as before.
Reasoning behind this can be found in a comment on top of the httpd-vhosts.conf:
The first VirtualHost section is used for all requests that do not match a ##ServerName or ##ServerAlias in any block.
That means when you type in localhost it fallbacks to your myapp.zend vhost because it is (probably) the first virtualhost section.