(PHP 4, PHP 5, PHP 7, PHP 8)
phpversion — Gets the current PHP version
Returns a string containing the version of the currently running PHP parser or extension.
extensionAn optional extension name.
   Returns the current PHP version as a string.
   If a string argument is provided for
   extension parameter, phpversion()
   returns the version of that extension, or false if there is no version
   information associated or the extension isn't enabled.
  
| Version | Description | 
|---|---|
| 8.0.0 | 
       extension is nullable now.
       | 
     
Example #1 phpversion() example
<?php
// Prints e.g. 'Current PHP version: 8.3.12'
echo 'Current PHP version: ' . phpversion();
// Prints e.g. '1.22.3' or nothing if the extension isn't enabled
echo phpversion('zip');
?>
Example #2 PHP_VERSION_ID example and usage
<?php
/**
 * 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 thePHP_*_VERSIONconstants.
Note:
Some extensions may define their own version number. However, most bundled extension will use the PHP version as their version number.