(PHP 4, PHP 5)
phpversion — Gets the current PHP version
Returns a string containing the version of the currently running PHP parser or extension.
An optional extension name.
If the optional extension parameter is specified, phpversion() returns the version of that extension, or FALSE if there is no version information associated or the extension isn't enabled.
Example #1 phpversion() example
<?php
// prints e.g. 'Current PHP version: 4.1.1'
echo 'Current PHP version: ' . phpversion();
// prints e.g. '2.0' or nothing if the extension isn't enabled
echo phpversion('tidy');
?>
Example #2 PHP_VERSION_ID example and usage
<?php
// PHP_VERSION_ID is available as of PHP 5.2.7, if our
// version is lower than that, then emulate it
if (!defined('PHP_VERSION_ID')) {
$version = explode('.', PHP_VERSION);
define('PHP_VERSION_ID', ($version[0] * 10000 + $version[1] * 100 + $version[2]));
}
// PHP_VERSION_ID is defined as a number, where the higher the number
// is, the newer a PHP version is used. It's defined as used in the above
// expression:
//
// $version_id = $major_version * 10000 + $minor_version * 100 + $release_version;
//
// Now with PHP_VERSION_ID we can check for features this PHP version
// may have, this doesn't require to use version_compare() everytime
// you check if the current PHP version may not support a feature.
//
// For example, we may here define the PHP_VERSION_* constants thats
// not available in versions prior to 5.2.7
if (PHP_VERSION_ID < 50207) {
define('PHP_MAJOR_VERSION', $version[0]);
define('PHP_MINOR_VERSION', $version[1]);
define('PHP_RELEASE_VERSION', $version[2]);
// and so on, ...
}
?>
Note:
This information is also available in the predefined constant PHP_VERSION. More versioning information is available using the PHP_VERSION_* constants.