NodeJS / Express: what is “app.use”?

Question

In the docs for the NodeJS express module, the example code has app.use(...).

What is the use function and where is it defined?

Answer 1

Middleware is a general term for software that serves to "glue together" so app.use is a method to configure the middleware, for example: to parse and handle the body of request: app.use(bodyParser.urlencoded({ extended: true })); app.use(bodyParser.json()); there are many middlewares you can use in your express application just read the doc : http://expressjs.com/en/guide/using-middleware.html