Mern.

batman.js

class Batman {

#realname = "Bruce Wayne";

getsuperheroname() {

return "This is batman";

}

getidentity() {

}

return "My secret identity is " + this.#realname;

}

module.exports = Batman;

super.js

class Superman {

#realname = "Clark Kent";

getsuperheroname() {

return "This is superman";

}

getidentity() {

return "My secret identity is " + this.#realname;

}

}

module.exports = Superman;

main.js

const BatmanClass = require("./batman.js");

const SupermanClass = require("./super.js");

const Batman = new BatmanClass();

const Superman = new SupermanClass();

console.log(Batman.getsuperheroname());

console.log(Batman.getidentity());

console.log(Superman.getsuperheroname());

console.log(Superman.getidentity());

pass.js

function CR(Marks, callback) {

console.log("checking result");

if (Marks >= 35) {

callback("passed");

} else {

callback("failed");

}

}

function DR(result) {

console.log("You have " + result);

}

CR(45, DR);

CR(30, DR);

pizza.js

const EventEmitter = require("node:events");

const emitter = new EventEmitter();

emitter.on("order_pizza", (size, topping) => {

console.log(`Order received! Baking a ${size} pizza with ${topping}`);

if (size === "large") {

console.log("Serving a complimentary drink");

}

});

emitter.emit("order_pizza", "medium", "mushroom");

emitter.emit("order_pizza", "large", "margherita");

show_status.js

function showstatus(msg, callback) {

console.log("status:" + msg);

callback();

function NextAct() {

console.log("Next Msg");

}

}

showstatus("loading completed:", NextAct);

showstatus("User authentication", NextAct);

RCB program 

class RCB {

  constructor(teamName, captainName, slogan) {

    this.teamName = teamName;

    this.captainName = captainName;

    this.slogan = slogan;

  }

  displayDetails() {

    console.log("Team Name:", this.teamName);

    console.log("Captain Name:", this.captainName);

  }

  printSlogan() {

    console.log(`Slogan: ${this.slogan}!`);

  }

  greetCaptain() {

    console.log(`Hello Captain ${this.captainName}, lead ${this.teamName} to victory!`);

  }

}

const rcbTeam = new RCB("Royal Challengers Bangalore", "Rajat Patidar", "Play Bold");

rcbTeam.displayDetails();

rcbTeam.printSlogan();

rcbTeam.greetCaptain();

Author program 

function Book(title, author, year) {

    this.title = title;

    this.author = author;

    this.year = year;

    

    this.getDetails = function() {

        console.log("Title: " + this.title);

        console.log("Author: " + this.author);

        console.log("Year: " + this.year);

    };

}

const book1 = new Book("Alice", "Cho", "2025");

const book2 = new Book("Last Day", "Gagan", "2025");

console.log("Book 1 Details:");

book1.getDetails();

console.log("Book 2 Details:");

book2.getDetails();