app.all(path, callback [, callback ...]) This method is like the standard

res.append(field [, value]) res.append() is supported by Express v4.11.0+

app.on('mount', callback(parent)) The mount event is fired on a sub-app, when it is mounted on a parent app. The parent app is

res.get(field) Returns the HTTP response header specified by field. The match is case-insensitive.

app.delete(path, callback [, callback ...]) Routes HTTP DELETE requests to the specified path with the specified callback functions. For more

req.param(name [, defaultValue]) Deprecated. Use either req.params, req.body or req

app.get(name) Returns the value of name app setting, where name is one of strings in the app settings table. For example:

req.app This property holds a reference to the instance of the Express application that is using the middleware. If

Define error-handling middleware functions in the same way as other middleware functions, except error-handling functions have four arguments instead of three: (err,

req.ip Contains the remote IP address of the request. When the trust proxy setting does not evaluate