what is node js and express js code example
Example 1: node.js express
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}`))
Example 2: node js express
basic server
const express =require('express');
const app = express();
const PORT = 5000;
app.get('/',(req,res)=>{
res.json({message: 'Welcome to the backend'})
})
app.listen(PORT ,()=>console.log(`Connected to ${PORT}`)
Example 3: express and node
// Load HTTP module
const http = require("http");
const hostname = "127.0.0.1";
const port = 8000;
// Create HTTP server
const server = http.createServer((req, res) => {
// Set the response HTTP header with HTTP status and Content type
res.writeHead(200, {'Content-Type': 'text/plain'});
// Send the response body "Hello World"
res.end('Hello World\n');
});
// Prints a log once the server starts listening
server.listen(port, hostname, () => {
console.log(`Server running at http://${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: require express server.js
const express = require('express')const app = express() app.get('/', function (req, res) { res.send('Hello World')}) app.listen(3000)
Example 6: express nodejs
Fast, unopinionated, minimalist web framework for Node.js