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

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

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.render(view, [locals], callback) Returns the rendered HTML of a view via the callback function. It accepts an optional parameter

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

res.set(field [, value]) Sets the response’s HTTP header field to value. To set multiple fields at once, pass an object

req.path Contains the path part of the request URL. // example.com/users

res.cookie(name, value [, options]) Sets cookie name to value. The value parameter may be a string or

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