# Understanding Objects in JavaScript

Hey Everyone,

In this blog, we will learn about **Objects** in Object-Oriented Programming in JavaScript.

When writing programs, we often need to store multiple values.

As your JavaScript programs grow, you will often need to store **related information together**.

For example, imagine storing information about a person:

*   Name
    
*   Age
    
*   City
    

Instead of creating separate variables for each value, JavaScript allows us to group them inside **objects**.

### What is an Object?

An **object** is a collection of **key–value pairs**.

Example:

```typescript
let person = {
  name: "Rahul",
  age: 25,
  city: "Delhi"
};
```

The keys describe the data, and the values store the actual information.

* * *

### Why Do We Need Objects?

Without objects, storing related information can become messy.

Example without objects:

```javascript
let name = "Rahul";
let age = 25;
let city = "Delhi";
```

Using an object:

```javascript
let person = {
  name: "Rahul",
  age: 25,
  city: "Delhi"
};
```

Everything related to the person is **grouped together in one structure**.

This makes code **cleaner and easier to manage**.

* * *

### Creating Objects

Objects are created using **curly braces** `{}`.

Example:

```javascript
let car = {
  brand: "Toyota",
  model: "Camry",
  year: 2023
};
```

Each property is written as:

```javascript
key : value
```

Properties are separated using commas.

* * *

### Accessing Object Properties

There are two ways to access object properties.

### 1\. Dot Notation

```javascript
let person = {
  name: "Rahul",
  age: 25
};

console.log(person.name); // Rahul
```

* * *

### 2\. Bracket Notation

```javascript
console.log(person["age"]); // 25
```

Bracket notation is useful when the property name is stored in a variable.

Example:

```javascript
let key = "name";

console.log(person[key]);
```

* * *

### Updating Object Properties

You can change the value of an existing property.

Example:

```plaintext
let person = {
  name: "Rahul",
  age: 25
};

person.age = 26;

console.log(person);
```

Output:

```javascript
{ name: "Rahul", age: 26 }
```

* * *

### Adding New Properties

You can also add new properties to an object.

Example:

```javascript
let person = {
  name: "Rahul",
  age: 25
};

person.city = "Delhi";

console.log(person);
```

Output:

```javascript
{ name: "Rahul", age: 25, city: "Delhi" }
```

* * *

### Deleting Properties

JavaScript provides the `delete` keyword to remove properties.

Example:

```javascript
let person = {
  name: "Rahul",
  age: 25,
  city: "Delhi"
};

delete person.city;

console.log(person);
```

Output:

```javascript
{ name: "Rahul", age: 25 }
```

* * *

### Looping Through Object Keys

We can use a **for in loop** to iterate through object properties.

Example:

```javascript
let person = {
  name: "Rahul",
  age: 25,
  city: "Delhi"
};

for (let key in person) {
  console.log(key, person[key]);
}
```

Output:

```javascript
name Rahul
age 25
city Delhi
```

This loop prints both **keys and values**.

* * *

### Object vs Array

Objects and arrays both store data, but they work differently.

| Feature | Array | Object |
| --- | --- | --- |
| Structure | Ordered list | Key–value pairs |
| Access method | Index | Property name |
| Example | `arr[0]` | `obj.name` |

Example:

Array:

```javascript
let arr = ["abhi", "naruto", "goku"];
```

Object:

```javascript
let fruit = {
  name: "Apple",
  color: "Red"
};
```

Arrays are best for **lists**, while objects are best for **structured data**.

* * *

### Practice Assignment

Try this in your browser console.

* * *

### Step 1: Create a Student Object

```javascript
let student = {
  name: "Aman",
  age: 20,
  course: "Computer Science"
};
```

* * *

### Step 2: Update One Property

```javascript
student.age = 21;
```

* * *

### Step 3: Add a New Property

```javascript
student.city = "Mumbai";
```

* * *

### Step 4: Print All Keys and Values

```javascript
for (let key in student) {
  console.log(key, student[key]);
}
```

* * *

And now, you know what are objects in JavaScript.

If you have any doubt or want to connect, feel free to drop a comment — I’d be happy to help.

Thanks for reading, and see you in the next blog!

Peace ✌️ and Happy Learning!