Node.js http.server.listening Property

// Node.js program to demonstrate the
// server.listening APi

// Importing http module
const http = require('http');

// Setting up PORT
const PORT = process.env.PORT || 3000;

// Creating http Server
const httpServer = http.createServer(
    function (request, response) {

        // getting the reference of the
        // underlying socket object
        // by using socket API
        const value = response.socket;

        // display result
        // by using end() api
        response.end("socket buffersize : "
            + value.bufferSize, 'utf8', () => {
                console.log("displaying the result...");

                // closing server
                // by using close() api
                httpServer.close(() => {
                    console.log("server is closed")
                })
            });
    });

// Listening to http Server
// by using listen() api
httpServer.listen(PORT, () => {
    console.log("Server is running at port 3000...");
});

// checking if the server is listening or not
if (httpServer.listening)
    console.log("server is listening")
else
    console.log("server is not listening")

// Node.js program to demonstrate the
// server.listening APi

// Importing http module
const http = require('http');

// Request and response handler
const http2Handlers = (request, response) => {

    // getting the reference of the
    // underlying socket object
    // by using socket API
    const value = response.socket;

    // display result
    // by using end() api
    response.end("socket local address : "
        + value.localAddress, 'utf8', () => {
            console.log("displaying the result...");

            // closing server
            // by using close() api
            httpServer.close(() => {
                console.log("server is closed")
            })
        });
};

// Listening to http Server
// by using listen() api
const httpServer = http.createServer(
    http2Handlers).listen(3000, () => {
        console.log("Server is running at port 3000...");
    });

// checking if the server is listening or not
if (httpServer.listening)
    console.log("server is listening")
else
    console.log("server is not listening")