Method getShortVersion

/**
 * Gets a "PHP standardized" version string for the current Joomla.
 *
 * @return  string  Version string.
 *
 * @since   1.5
 */
public function getShortVersion() : string
{
    $version = self::MAJOR_VERSION . '.' . self::MINOR_VERSION . '.' . self::PATCH_VERSION;
    if (!empty(self::EXTRA_VERSION)) {
        $version .= '-' . self::EXTRA_VERSION;
    }
    return $version;
}