Route Parameters

Summary

Dynamic segments in a URL path (`/users/:id`) captured into `req.params` — how you identify a specific resource in a RESTful API.

• 1Build a route with multiple params, e.g. `/users/:userId/posts/:postId`.
• 2Validate that a param is the expected type/format before using it in a DB query.
• 3Learn optional params and simple pattern matching in Express routes.