JavaScript Objects

In JavaScript, an object is used to store related data and information in one place.

For example, if you want to store information about a user, you can create an object with properties such as name, age, email, and city.

const user = {
    name: "John",
    age: 25,
    email: "john@example.com",
    city: "Jaipur"
};

Here, user is an object.

What Is a JavaScript Object?

A JavaScript object stores data using key-value pairs.

const person = {
    name: "John",
    age: 25
};

In this example:

• name is a key
• "John" is its value
• age is a key
• 25 is its value

An object can contain multiple properties.

How to Create an Object

The easiest way to create an object is by using curly brackets {}.

const car = {
    brand: "Toyota",
    model: "Camry",
    year: 2025
};

The object contains three properties:

brand → Toyota
model → Camry
year  → 2025

How to Access Object Properties

There are two common ways to access an object property.

1. Dot Notation

console.log(car.brand);

Output:

Toyota

2. Bracket Notation

console.log(car["model"]);

Output:

Camry

Both methods can be used to access object properties.

How to Change an Object Property

You can easily change the value of an existing property.

car.year = 2026;

console.log(car.year);

Output:

2026

How to Add a New Property

You can also add a new property to an existing object.

car.color = "Black";

console.log(car.color);

Output:

Black

Now the object contains:

const car = {
    brand: "Toyota",
    model: "Camry",
    year: 2026,
    color: "Black"
};

How to Delete a Property

Use the delete keyword to remove a property.

delete car.color;

Now the color property has been removed from the object.

Objects Can Contain Functions

An object can also contain functions. A function inside an object is commonly called a method.

const user = {
    name: "John",

    greet: function() {
        console.log("Hello!");
    }
};

user.greet();

Output:

Hello!

You can also write the method using modern JavaScript syntax:

const user = {
    name: "John",

    greet() {
        console.log("Hello!");
    }
};

user.greet();

Objects Can Contain Different Data Types

JavaScript objects can store different types of values.

const product = {
    name: "Laptop",
    price: 50000,
    available: true,
    categories: ["Laptop", "Electronics"]
};

Here we have:

• name → string
• price → number
• available → boolean
• categories → array

Objects can even contain another object.

const user = {
    name: "John",
    address: {
        city: "Jaipur",
        country: "India"
    }
};

You can access the city like this:

console.log(user.address.city);

Output:

Jaipur

JavaScript Objects Example

Here is a simple real-world example:

const student = {
    name: "Rahul",
    age: 22,
    course: "JavaScript",
    isActive: true
};

console.log(student.name);
console.log(student.course);

Output:

Rahul
JavaScript

Conclusion

JavaScript objects are an important part of JavaScript. They allow you to group related information using key-value pairs.

You will use objects frequently when working with APIs, JSON, databases, web applications, React, Node.js, and JavaScript projects.