how to create a server in express js code example

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: how to make an express server

// this is your code
// ZDev1#4511 on discord if you want more help!
// first you should install express in the terminal
// `npm i express`.
const express = require('express');
const app = express();

// route
app.get('/', (req,res)=>{
  // Sending This is the home page! in the page
  res.send('This is the home page!');
});

// Listening to the port
let PORT = 3000;
app.listen(PORT)

// FINISH!

Example 3: create server with express js

// npm init
// npm i express

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

const PORT = 3000;

// Body parser
server.use(express.json());

// Homme page
server.get('/', (req, res) => {
  return res.send("<h1 style='text-align: center;'>Hello,<br />from the Express.js server!</h1>");
})

// About page
server.get('/about', (req, res) => {
  return res.send('<h2 style="text-align:center">About us</h2>');
})

// 404 page
server.use((req, res, next) =>{
  res.status(404);

  // respond with html page
  if (req.accepts('html')) {
    res.sendFile(__dirname + '/error404.html');
    return;
  }
  // respond with json
  else if (req.accepts('json')){
    res.send({
      status: 404,
      error: 'Not found'
    });
    return;
  }
  // respond with text
  else {
    res.type('txt').send('Error 404 - Not found');
  }
});

// Listening to the port
server.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}`);
});

Example 4: require express server.js

const express = require('express')const app = express() app.get('/', function (req, res) {  res.send('Hello World')}) app.listen(3000)