How to know what version of PHP is used on my xampp?

Put this in your root directory:

<?php
phpinfo();
?>

Save it as phpinfo.php and point your browser to it (this could be http://localhost/phpinfo.php)

• More information (you can get much more information than just the version).
• Example (random image):

Try with command from terminal

sudo /opt/lampp/bin/php -v

first you have to need the version of your Xampp

xampp -v 

or

xampp --version

Then you can check the php version from xampp website

you can't know it from command line since it's bundled inside the Xampp