Express Router and Modular Routing

As Express applications grow, defining all routes in a single file (e.g., server.js) becomes unmanageable. A monolithic structure results in messy, hard-to-debug code, making scaling difficult. To improve maintainability, a well-structured application should use modular routes, organizing related routes into separate files.

Express provides express.Router(), a built-in feature for creating modular route handlers. This improves:

• Code organization: Each module handles only its relevant routes.

• Maintainability: It is easier to debug and extend.

• Reusability: Routes can be packaged into standalone modules.

Using Express router for modular routes

Express allows us to create modular routes using express.Router(), which returns a new instance of the Router class. This instance allows us to define routes and middleware separately before integrating them into the main Express application, ensuring a more modular and organized structure. The following example demonstrates a modular route file (users.js) that defines routes independently, which can later be integrated into the main application.