This document provides an introduction to Express, a lightweight web application framework for Node.js. It discusses what Express is, alternatives to Express, and provides an example "Hello World" Express app. It also covers how to create routers in Express to handle requests and routes, and provides an exercise to create an app with three routes. Finally, it mentions making the routers modular by exposing them in separate modules.

1. Express Introduction
Ahmed Elbassel
Email: elbassel.n13@gmail.com
Skype: ahmed_elbassel

2. Express Introduction
1. What is Express?
2. Express Alternatives
3. Hello World, Express example
4. Creating Routers
5. Exercise
6. Make Routers in a separate modules.

3. 1.What is Express?
- Express 3.x is a light-weight web application framework to help organize your
web application into an MVC architecture on the server side.
- Express is a routing and middleware web framework that has minimal
functionality of its own: An Express application is essentially a series of
middleware function calls.
- http://expressjs.com/

4. 2. Express Alternatives

5. 3. Hello World, Express Example

6. 4. Creating Routers
- A router object is an isolated instance of middleware and routes. You can
think of it as a “mini-application,” capable only of performing middleware and
routing functions.
- You can call the router as Controller.
- To create a router:

7. 4. Creating Routers
- Handle incoming requests:
- router.METHOD(path, [callback, ...] callback)
- Finally, add the router to express application:

8. 5. Exercise
- Write an app with three routes; all them to provide some data; to provide the
following:
- /home: reply with greeting message from the home page
- /contacts: reply with your contacts.
- /profiles: reply with your profile

9. 6. Make router in a separate modules
- It’s too simple, expose the router in a module.

10. Questions