how to run the Express server code example

Example 1: 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 2: simple express server

const express = require('express');
const app = express();
const mongoose = require('mongoose');
const bodyParser = require('body-parser');

app.use(bodyParser.json());
const PORT = process.env.PORT || 3000;

app.use(bodyParser.json());

//connecting to db
try {
    mongoose.connect('mongodb://localhost/YOUR_DB_NAME', {
        useNewUrlParser: true,
        useUnifiedTopology: true,
      	useCreateIndex: true,
      }, () =>
      console.log("connected"));
  } catch (error) {
    console.log("could not connect");
  }

app.get('/', (req, res) => {
  res.send('<h1>Some HTML</h1>');
  res.send('<p>Even more HTML</p>');
});



app.listen(PORT, () => console.log(`Server is listening on port ${PORT}`));