What is Routing?

• Routing in Express is the process of defining URL paths and associating them with HTTP request methods (GET, POST, PUT, DELETE, etc.) and controller functions.
• Each route tells Express what to do when a specific URL is hit.

Example Routing

// routes/userRoutes.js

const express = require("express");
const router = express.Router();
const userController = require("../controllers/userController");

router.get("/users", userController.getAllUsers);
router.post("/users", userController.createUser);

module.exports = router;

• router.get() → Handles GET requests
• router.post() → Handles POST requests
• Connects routes to the respective controller functions.

Integrating Routes in Main App

const express = require("express");
const app = express();
const userRoutes = require("./routes/userRoutes");

app.use(express.json());
app.use("/api", userRoutes);

app.listen(3000, () => {
  console.log("Server running on port 3000");
});

• app.use("/api", userRoutes) — Prefixes all user routes with /api

Key Points

• Controllers handle the logic
• Routes handle the URL structure and HTTP method mapping
• Keeping them separate improves code readability, structure, and scalability.