express

express

Build Express.js web servers and REST APIs.

Middleware System

• Chain request handlers via app.use() and app.VERB()
• Order matters: middleware runs top-down
• Error middleware has 4 params: (err, req, res, next)

Routing

• Express Router for modular route groups
• Route params :id with req.params
• Query strings with req.query
• Body parsing via express.json() and express.urlencoded()