- var_dump: documentation ( source)
- version_compare: documentation ( source)
- define: documentation ( source)
<?php
define('DEFINED', '1.3.0.0');
$version = '1.6.1.1';
var_dump ( version_compare(DEFINED, $version, '>'));
var_dump ( version_compare(NOT_DEFINED, $version, '>'));
var_dump ( version_compare(DEFINED, $version, '<'));
var_dump ( version_compare(NOT_DEFINED, $version, '<'));