module.exports[404] = function pageNotFound(req, res) {
  // file path name, render engine will add the .html
  const viewFilePath = '404';
  // status code of error, 404 being page not found
  const statusCode = 404;
  // setup a result, not really needed but for future
  // multiple status codes, this is useful
  const result = {
    status: statusCode
  };

  res.status(result.status);
  // render the file path to the view when this function is called
  res.render(viewFilePath, {}, (err, html) => {
    // if there is an error
    if (err) {
      // then render the error instead of the view
      return res.status(res.status).join(result);
    }
    // otherwise display the viewFilePath+'.html' file
    res.send(html);
  });
};