# Understanding Objects in JavaScript

Hey there, in this article we learn about the objects in js, why objects are being used, ohw to loop over the objects, different methods to handle the looping on object keys,values and complete single entry.

### What are Objects ?

**Objects in JavaScript** are a fundamental data type used to store collections of key-value pairs and represent complex entities

Example information about a person:

```plaintext
Name → Rahul
Age → 22
City → Delhi
```

> Instead of storing these values in separate variables, we can group them together inside an **object**.

### Why Do We Need Objects?

Objects help us organize **related data in a structured way**.

```javascript
// without object
let name = "Rahul";
let age = 22;
let city = "Delhi";

// with object
let person = {
  name: "Rahul",
  age: 22,
  city: "Delhi"
};
```

### Creating an Object

Objects are created using **curly braces** `{}`. Inside the braces, we define **key-value pairs**.

### Syntax

```javascript
let objectName = {
  key: value
};
```

### Accessing Object Properties

There are **two ways** to access object properties.

### Dot Notation

This is the most common method.

```javascript
let person = {
  name: "Rahul",
  age: 22,
  city: "Delhi"
};

console.log(person.name); // Rahul
console.log(person.age); // 22
```

### Bracket Notation

Bracket notation uses square brackets.

```javascript
console.log(person["city"]);
```

### Updating Object Properties

Object values can be updated easily.

```javascript
let person = {
  name: "Rahul",
  age: 22
};

person.age = 23;

console.log(person.age); // 23
```

### Adding New Properties

We can add new properties to an object anytime.

```javascript
let person = {
  name: "Rahul",
  age: 22
};

person.city = "Mumbai";

console.log(person); // { name: "Rahul", age: 22, city: "Mumbai" }
```

### Deleting Properties

To remove a property, we use the **delete** keyword.

```javascript
let person = {
  name: "Rahul",
  age: 22,
  city: "Delhi"
};

delete person.city;

console.log(person); // { name: "Rahul", age: 22 }
```

### Looping Through Object Keys

We can loop through object properties using a **for...in loop**.

### Example

```javascript
let person = {
  name: "Rahul",
  age: 22,
  city: "Delhi"
};

for (let key in person) {
  console.log(key, person[key]);
} 
// Expected Output--
// name Rahul
// age 22
// city Delhi
```

### Array vs Object

**Arrays** store ordered collections of values using **numeric indices** (starting from 0). They are ideal for lists where **order matters**, such as a sequence of numbers, strings, or objects.

**Objects** store data as **key-value pairs**, where keys are typically strings (or symbols) and values can be any data type. They are used to represent **entities** with properties, like a person, car, or configuration.