node js express documentation code example

Example 1: express request path

// GET 'http://www.example.com/admin/new?a=b'
app.get('/admin', (req, res, next) => {
  req.originalUrl; // '/admin/new?a=b' (full path with query string)
  req.baseUrl; // '/admin'
  req.path; // '/new'
  req.baseUrl + req.path; // '/admin/new' (full path without query string)
});

Example 2: express redirect

res.redirect('/foo/bar')
res.redirect('http://example.com')
res.redirect(301, 'http://example.com')
res.redirect('../login')

Example 3: express and node

// Load HTTP module
const http = require("http");

const hostname = "127.0.0.1";
const port = 8000;

// Create HTTP server 
const server = http.createServer((req, res) => {

   // Set the response HTTP header with HTTP status and Content type
   res.writeHead(200, {'Content-Type': 'text/plain'});
   
   // Send the response body "Hello World"
   res.end('Hello World\n');
});

// Prints a log once the server starts listening
server.listen(port, hostname, () => {
   console.log(`Server running at http://${hostname}:${port}/`);
})

Example 4: node js express

// node js -> express -> basic example: static folder, 404 page

const express = require('express');
const path = require('path');
const PORT = process.env.PORT || 5000;

const app = express();

function error404(req, res) {
  res.status(404);

  if (req.accepts('html')) {
    res.sendFile(path.join(__dirname, 'public/errors/404.html'));
    return;
  }

  if (req.accepts('json')) {
    res.send({
      status: 404,
      error: 'Not found'
    });
    return;
  }
  
  res.type('txt').send('404 - Not found');
}

app
  .use(express.static(path.join(__dirname, 'public')))
  .use(error404)
  .listen(PORT, () => console.log(`Listening on ${ PORT }`));

Example 5: express js

Express.js, or simply Express, is a web application framework for Node.js,
released as free and open-source software under the MIT License.

It is designed for building web applications and APIs.
It has been called the de facto standard server framework for Node.js.

Example 6: node js http request express

npm install request@2.81.0