Example 1: express.js server
/* ====== create node.js server with express.js framework ====== */
// dependencies
const express = require("express");
const app = express();
app.get("/", (req, res) => {
res.send("This is home page.");
});
app.post("/", (req, res) => {
res.send("This is home page with post request.");
});
// PORT
const PORT = 3000;
app.listen(PORT, () => {
console.log(`Server is running on PORT: ${PORT}`);
});
// ======== Instructions ========
// save this as index.js
// you have to download and install node.js on your machine
// open terminal or command prompt
// type node index.js
// find your server at http://localhost:3000
Example 2: express hello world
//to run : node filename.js
const express = require('express')
const app = express()
const port = 3000
app.get('/', (req, res) => res.send('Hello World!'))
app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))
//visit localhost:3000
// assuming you have done 1) npm init 2) npm install express
Example 3: sample express app
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:${port}`))
Example 4: node.js express
const express = require('express')
const app = express()
const port = 3000
app.get('/', (req, res) => res.send('Hello World!'))
app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))
Example 5: 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 6: 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 }`));