express router parameters code example

Example 1: express hello world

//to run : node filename.js
const express = require('express')
const app = express()
const port = 3000

app.get('/', (req, res) => res.send('Hello World!'))

app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))

//visit localhost:3000
// assuming you have done 1) npm init 2) npm install express

Example 2: express get url parameters

app.get('/path/:name', function(req, res) {
  res.send("tagId is set to " + req.params.name);
});

Example 3: express route parameters

app.get('/users/:userId/books/:bookId', function (req, res) {
  res.send(req.params)
})

Example 4: express url redirect

const app = require('express')();

// The `res.redirect()` function sends back an HTTP 302 by default.
// When an HTTP client receives a response with status 302, it will send
// an HTTP request to the URL in the response, in this case `/to`
app.get('/from', (req, res) => {
  res.redirect('/to');
});
app.get('/to', (req, res) => res.send('Hello, World!'));

Example 5: express route parameters

Route path: /flights/:from-:to
Request URL: http://localhost:3000/flights/LAX-SFO
req.params: { "from": "LAX", "to": "SFO" }