Routes, Middleware, and Controllers in Express.js

Syntax of a Route in Express

Middleware vs. Route Handler

Examples

Express route with a single handler function

Express route with multiple middleware functions

Express route with an array of middleware functions

Express route with a combination of an array of middleware functions and individual callbacks

Important Things to Know about the next Parameter

Categories of Middleware in Express.js

Application-level middleware

Router-level middleware

Error-handling middleware

Built-in middleware

Third-party middleware

Note: Middleware categories in Express are not mutually exclusive