Get File Extension

    /*
    - Get File Extension
    - Gets the file extension from the file's name.

    $fileName      - The name of the file to get the extension of.
    $includePeriod - Whether or not to include the prefix period (eg. ".txt")
    */

    public function getFileExtension($fileName, $includePeriod = true) {
        if (strpos($fileName, ".")) {
            $sides = explode(".", $fileName);
            $ext = "";

            if ($includePeriod)
                $ext .= ".";

            $ext .= $sides[count($sides) - 1];
            return $ext;
        } else
            return "N/A";
    }