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

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

Overview Express 4 is a breaking change from Express 3, so. That means an existing Express 3 app will not work if you update

app.METHOD(path, callback [, callback ...]) Routes an HTTP request, where METHOD is the HTTP method of the request, such as GET, PUT, POST,

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

Use the app.engine(ext, callback) method to create your own template engine. ext refers to the file extension, and callback is the template

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

req.cookies When using cookie-parser middleware,

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