where php.ini file is located in xampp code example

Example: php.ini file location in xampp

Write the following inside phpini_path.php( or AnyNameAsYouLike.php) and run it in the browser.

<?php phpinfo();?>
Among various other parameters you'll get Loaded Configuration File parameter which value is the path of php.ini on the server.

The location of php.ini depends on server operating system:

Windows (With Xampp Installation):

/xampp/php/php.ini 
macOS, OS X:

/private/etc/php.ini
Linux:

/etc/php.ini
/usr/bin/php5/bin/php.ini
/etc/php/php.ini
/etc/php5/apache2/php.ini