Routing refers to setting up responses to client requests at designated endpoints.
For example, a clothing site could have endpoints /shoes, /tees, and /pants. The client could request data from these endpoints through a URI, like example.com + [endpoint], and an HTTP request method (GET, POST, etc.). The default request method is GET.
When a web application receives a request, it can send a file or serve up a webpage as a response.
Below is the default structure of a route in Express:
app.METHOD(PATH, HANDLER)
app is an instance of Express
METHOD is an HTTP express method
PATH is the endpoint
HANDLER is the function executed when a request is received from the path
const express = require('express')const app = express()const port = 3000app.get('/', (req, res) => res.send('Hello World!'))app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))
Requires the express module and puts it in a variable (line 1)
Calls the express function and creates an instance of the Express application to the app variable (line 2)
Creates a variable port equal to 3000 (line 3)
App starts server and listens for connections to port 3000 (line 7)
Listens for requests to the the root URL / and sends the response “Hello World!” (line 5)
To see the output on a local browser, run the app with the command node app.js. Then, load http://localhost:3000/ in a browser to see the output.
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