This code demonstrates a simple way to validate IP address using preg_match() PHP function. This is a very simple code, that allows you to perform this task quickly with a minimum lines of code.

<?php
$ip_address = '127.0.0.1';
 
if(preg_match('/^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$/', $ip_address)){
   echo 'IP address is valid!';
}else{
   echo 'IP address is NOT valid!';
}
?>