app.locals The app.locals object has properties that are local variables within the application.

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

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

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

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

Overview This article discusses performance and reliability best practices for Express applications deployed to production

app.disable(name) Sets the Boolean setting name to false, where name is one of the properties from the

Routing refers to determining how an application responds to a client request to a particular endpoint, which is a URI (or path) and a specific HTTP request method

Overview Middleware functions are functions that have access to the request object (req), the response object (res)

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