Steps to create a WEBSERVER using NODE.JS

$ node -v 
v14.16.1

var foo = 'hello world'
console.log(foo)

$ node filename

// 1. Use require to load fs core usage module var file = require('fs')

// 2. Read the file file.readFile('hello.txt', function(error, data){
    // The file is stored in binary by default and needs toString
    if (error != null) {
        console.log('file dons not exits or read fail')
        return
    }
    console.log(data.toString())
})

// 3. Write file // File path file content callback function file.writeFile('hello.txt', 'hello world', function(error, data){
    if (error != null) {
        console.log('write fail')
        return
    }
    console.log('write success')
})

// 1. Use require to load the http core usage module var http = require('http')

// 2. http.createServer creates a server instance var server = http.createServer()

// 3. Create a request response server.on('request', function(request, response){
    console.log('Requesting interface...')
    response.write('Hello World')
    // The end method must end response.end()
})

// 4. Bind the port number to start the server server.listen(8090, function(){
    console.log('Server running at http://127.0.0.1:8090/')
})

var http = require('http')

var server = http.createServer();

server.on('request', function(request, response){
    // Get the request path var url = request.url
    
    // Return different information based on the request path if (url == '/') {
        response.end('index page')
    } else if (url == '/login') {
        response.end('login page')
    } else {
        response.end('404 page')
    }
  
})

server.listen('8081', function(){
    console.log('Server running at http://127.0.0.1:8081/');
})

[
    {
        "name": "Iphone 12",
        "price": 6799
    },
    {
        "name": "MacBook Air M1",
        "price": 7999
    }
]

if (url == '/products') {
    var products = [
        {
            name : 'Iphone 12',
            price : 6799
        },
        {
            name : 'MacBook Air M1',
            price : 7999
        }
    ]
    response.end(JSON.stringify(products))
}