how to start server with node code example

Example 1: how to create node js server

/* ====== create node.js server with core 'http' module ====== */
// dependencies
const http = require("http");

// PORT
const PORT = 3000;

// server create
const server = http.createServer((req, res) => {
   if (req.url === "/") {
      res.write("This is home page.");
      res.end();
   } else if (req.url === "/about" && req.method === "GET") {
      res.write("This is about page.");
      res.end();
   } else {
      res.write("Not Found!");
      res.end();
   }
});

// server listen port
server.listen(PORT);

console.log(`Server is running on PORT: ${PORT}`);

/* ========== *** ========== */

/* ====== 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: create node js server

import express from 'express';
const server = express();

const port = 8080;

server.get('/', (req, res) => {
  return res.send('Hello, Express.js!');
})

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

Example 3: srart server js

require('dotenv').config();

const express = require('express');
const server = express();
const cors = require('cors');
const ejs = require('ejs');
const methodOverride = require('method-override');
const pg = require('pg');
const agent = require('superagent');

const client = new pg.Client(process.env.DATABASE_URL);

server.use(methodOverride('_method'));
server.use(express.static('./public'));
server.use(cors());
server.use(express.urlencoded({extended :true}));
server.set('view engine','ejs');