Basic Routing

Where to, Scotty?

In Express, Routing is our GPS. It determines how our application responds to a client request for a particular endpoint.

The structure is simple: app.METHOD(PATH, HANDLER).

• app: The instance of express.
• METHOD: The HTTP request method (get, post, put, delete, etc.).
• PATH: A path on the server.
• HANDLER: The function executed when the route is matched.

The Interchange

Fig 1: The Routing Logic. Follow the colors or get lost in traffic.

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Our First Route

// The "GET" Lane -> Retrieve Info
// Path: Root ("/")
app.get('/', (req, res) => {
  res.send('Engine Online. Hello Express!');
});

// Path: /things
app.get('/things', (req, res) => {
  res.send('Here is the list of things you asked for.');
});

Solo Warning: Express matches routes in the order they are defined. First match wins. If you have two routes for /things, the second one will never be reached. Traffic doesn’t loop back.

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Extra Bits & Bytes

Basic Express Routing - Demo Repo

⏭ Designated Lanes

We can handle generic traffic. Now let’s talk about specific targets using named route parameters.