Routing menentukan bagaimana aplikasi merespons request ke URL tertentu.

Path parameters (:param):

// GET /users/42
app.get("/users/:id", (req, res) => {
  const userId = req.params.id; // "42"
  res.json({ userId });
});

// GET /posts/5/comments/3
app.get("/posts/:postId/comments/:commentId", (req, res) => {
  const { postId, commentId } = req.params;
  res.json({ postId, commentId });
});

Query string (?key=value):

// GET /search?q=javascript&page=2
app.get("/search", (req, res) => {
  const { q, page } = req.query;
  res.json({ query: q, page: parseInt(page) || 1 });
});

Multiple HTTP methods:

// CRUD untuk resource "users"
app.get("/users", ...);       // List semua
app.get("/users/:id", ...);   // Detail satu
app.post("/users", ...);      // Buat baru
app.put("/users/:id", ...);   // Update
app.delete("/users/:id", ...); // Hapus

RESTful Convention: