13. Objects in JavaScript – Programs

Object Creation Techniques

Method 1 – Object Literal

				
					Best for beginners.
let student = {
    name: "Amit",
    marks: 80,
    getResult() {
        return this.marks >= 40 ? "Pass" : "Fail";
    }
};

console.log(student.getResult());

Method 2 – Using new Object()

				
					let car = new Object();
car.brand = "Toyota";
car.year = 2024;

console.log(car.brand);

Method 3 – Constructor Function

				
					function Student(name, marks) {
    this.name = name;
    this.marks = marks;
    this.getResult = function () {
        return this.marks >= 40 ? "Pass" : "Fail";
    };
}

let s1 = new Student("Neha", 90);
console.log(s1.getResult());

Method 4 – ES6 Class (Modern & Professional)

				
					class Student {
    constructor(name, marks) {
        this.name = name;
        this.marks = marks;
    }

    getResult() {
        return this.marks >= 40 ? "Pass" : "Fail";
    }
}

let s1 = new Student("Riya", 85);
console.log(s1.getResult());

Practice Programs on JavaScript Objects

Program 1 – Student Result System

				
					const student = {
    name: "Amit",
    marks: [78, 85, 90, 66, 88],

    total() {
        return this.marks.reduce((sum, m) => sum + m, 0);
    },

    average() {
        return this.total() / this.marks.length;
    },

    grade() {
        const avg = this.average();
        if (avg >= 90) return "A+";
        if (avg >= 75) return "A";
        if (avg >= 60) return "B";
        return "C";
    }
};

console.log(student.name, student.grade());

Program 2 – Simple Bank Account

				
					const account = {
    holder: "Riya",
    balance: 5000,

    deposit(a) { this.balance += a; },
    withdraw(a) { this.balance -= a; },

    show() { console.log("Balance:", this.balance); }
};

account.deposit(2000);
account.withdraw(500);
account.show();

Program 3 – Employee with Salary Parts

				
					const employee = {
    name: "Rahul",
    salary: { basic: 30000, hra: 8000, bonus: 2000 },

    total() {
        return this.salary.basic + this.salary.hra + this.salary.bonus;
    }
};

console.log(employee.total());

Program 4 – Shopping Cart

				
					const cart = {
    items: [
        { name: "Book", price: 300, qty: 2 },
        { name: "Pen", price: 20, qty: 5 }
    ],

    total() {
        return this.items.reduce((t, i) => t + i.price * i.qty, 0);
    }
};

console.log(cart.total());

Program 5 – Attendance Tracker

				
					const classRoom = {
    students: [
        { name: "A", present: true },
        { name: "B", present: false }
    ],

    presentCount() {
        return this.students.filter(s => s.present).length;
    }
};

console.log(classRoom.presentCount());

Program 6 – Mobile Price After Discount

				
					const mobile = {
    brand: "Samsung",
    price: 20000,
    discount: 10,

    final() {
        return this.price - this.price * this.discount / 100;
    }
};

console.log(mobile.final());

Program 7 – Library Object

				
					const library = {
    books: ["JS", "Python"],

    add(book) { this.books.push(book); },
    list() { this.books.forEach(b => console.log(b)); }
};

library.add("Java");
library.list();

Program 8 – Movie Rating

				
					const movie = {
    title: "Action Film",
    ratings: [4, 5, 3, 4],

    average() {
        return this.ratings.reduce((a, b) => a + b) / this.ratings.length;
    }
};

console.log(movie.average());

Program 9 – Weather Report

				
					const weather = {
    city: "Delhi",
    temp: 30,
    unit: "C",

    report() {
        return `${this.city}: ${this.temp}°${this.unit}`;
    }
};

console.log(weather.report());

Program 10 – To-Do Manager

				
					const todo = {
    tasks: [],

    add(task) { this.tasks.push(task); },
    show() { console.log(this.tasks); }
};

todo.add("Study");
todo.add("Practice");
todo.show();

Program 11 – Nested User Profile

				
					const user = {
    name: "Amit",
    address: { city: "Delhi", pin: 110045 }
};

console.log(user.address.pin);

Program 12 – Batch with Students

				
					const batch = {
    trainer: "Mr. X",
    students: ["A", "B", "C"]
};

console.log(batch.students.join(", "));

Program 13 – Report Card

				
					const report = {
    name: "Neha",
    subjects: [
        { sub: "Math", marks: 90 },
        { sub: "Sci", marks: 80 }
    ],

    total() {
        return this.subjects.reduce((t, s) => t + s.marks, 0);
    }
};

console.log(report.total());

Program 14 – Inventory Check

				
					const store = {
    products: [
        { name: "Mouse", qty: 5 },
        { name: "Keyboard", qty: 3 }
    ],

    check(name) {
        return this.products.find(p => p.name === name)?.qty || 0;
    }
};

console.log(store.check("Mouse"));

Program 15 – Clone & Modify

				
					const original = { name: "Amit", age: 20 };
const copy = { ...original };
copy.age = 25;

console.log(original, copy);

Program 16 – Student Constructor

				
					function Student(name, marks) {
    this.name = name;
    this.marks = marks;

    this.result = function () {
        return this.marks >= 40 ? "Pass" : "Fail";
    };
}

const s1 = new Student("Amit", 70);
console.log(s1.result());

Program 17 – Product Constructor

				
					function Product(name, price) {
    this.name = name;
    this.price = price;
}

const p = new Product("Laptop", 50000);
console.log(p.name);

Program 18 – Bank Constructor

				
					function Bank(balance) {
    this.balance = balance;
    this.deposit = amt => this.balance += amt;
}

const b = new Bank(1000);
console.log(b.deposit(500));

Program 19 – Course Constructor

				
					function Course(title, duration) {
    this.title = title;
    this.duration = duration;
}

const c = new Course("Web Dev", "6 months");
console.log(c.title);

Program 20 – Cart Item Constructor

				
					function Item(name, price, qty) {
    this.name = name;
    this.price = price;
    this.qty = qty;

    this.total = () => this.price * this.qty;
}

const i = new Item("Pen", 10, 5);
console.log(i.total());

Program 21 – Car Class

				
					class Car {
    constructor(brand) {
        this.brand = brand;
    }
}

const car1 = new Car("Toyota");
console.log(car1.brand);

Program 22 – Employee Class

				
					class Employee {
    constructor(name, salary) {
        this.name = name;
        this.salary = salary;
    }

    annual() {
        return this.salary * 12;
    }
}

const e = new Employee("Ravi", 30000);
console.log(e.annual());

Program 23 – Login System

				
					class UserLogin {
    constructor(user, pass) {
        this.user = user;
        this.pass = pass;
    }

    login(p) {
        console.log(p === this.pass ? "Success" : "Wrong");
    }
}

const u = new UserLogin("admin", "123");
u.login("123");

Program 24 – Hotel Booking

				
					class Hotel {
    constructor(rooms) {
        this.rooms = rooms;
    }

    book() {
        if (this.rooms > 0) this.rooms--;
    }
}

const h = new Hotel(2);
h.book();
console.log(h.rooms);

Program 25 – Flight Booking

				
					class Flight {
    constructor(seats) {
        this.seats = seats;
    }

    reserve() {
        if (this.seats > 0) this.seats--;
    }
}

const f = new Flight(5);
f.reserve();
console.log(f.seats);

Program 26 – Order System

				
					class Order {
    constructor() {
        this.items = [];
    }

    add(name, price, qty) {
        this.items.push({ name, price, qty });
    }

    total() {
        return this.items.reduce((t, i) => t + i.price * i.qty, 0);
    }
}

const o = new Order();
o.add("Phone", 20000, 1);
console.log(o.total());

Program 27 – Wallet

				
					class Wallet {
    constructor(balance) {
        this.balance = balance;
    }

    pay(amount) {
        if (amount <= this.balance) this.balance -= amount;
    }
}

const w = new Wallet(1000);
w.pay(200);
console.log(w.balance);

Program 28 – Quiz System

				
					class Quiz {
    constructor() {
        this.score = 0;
    }

    correct() { this.score++; }
}

const q = new Quiz();
q.correct();
console.log(q.score);

Program 29 – Membership Validity

				
					class Member {
    constructor(expiry) {
        this.expiry = new Date(expiry);
    }

    valid() {
        return this.expiry > new Date();
    }
}

const m = new Member("2026-12-31");
console.log(m.valid());

Program 30 – Parking Lot

				
					class Parking {
    constructor(spaces) {
        this.spaces = spaces;
    }

    park() {
        if (this.spaces > 0) this.spaces--;
    }
}

const p = new Parking(3);
p.park();
console.log(p.spaces);