req.is(type) Returns true if the incoming request’s “Content-Type” HTTP header field matches the MIME type specified by the type

req.query This property is an object containing a property for each query string parameter in the route. If there is no query string, it is

req.subdomains An array of subdomains in the domain name of the request. //

req.get(field) Returns the specified HTTP request header field (case-insensitive match). The Referrer and Referer

req.cookies When using cookie-parser middleware,

req.stale Indicates whether the request is “stale,” and is the opposite of req.fresh. For more information, see

req.ips When the trust proxy setting does not evaluate to false, this property contains an array of IP addresses specified