# 30 Days of JAVASCRIPT #7/30

### **2.Object Data Structure in JavaScript**

In JavaScript, an object is a collection of key-value pairs, also known as a map, dictionary, or hash-table. Objects are a fundamental data structure in JavaScript and are used extensively in the language

#### **Creating Objects**

To create an object in JavaScript, we can use object literal syntax, which involves enclosing the key-value pairs in curly braces`{}`. For example, we can create an object representing a person with the following code:

```javascript
javascript
const person = {
  name: "John",
  age: 30,
  occupation: "Developer"
};
```

We can also create an object using a constructor function, which is a function that returns a new object. For example, we can create a`Person`constructor function that takes in a name, age, and occupation and returns a new object with those properties:

```javascript
javascript
function Person(name, age, occupation) {
  this.name = name;
  this.age = age;
  this.occupation = occupation;
}

const person = new Person("John", 30, "Developer");
```

#### **Accessing Object Properties**

We can access the properties of an object using dot notation or bracket notation. For example, to access the`name`property of the`person`object we created earlier, we can use the following code:

```javascript
javascript
console.log(person.name); // Output: "John"
```

Alternatively, we can use bracket notation to access the`name`property:

```javascript
javascript
console.log(person["name"]); // Output: "John"
```

#### **Modifying Object Properties**

We can modify the properties of an object by assigning a new value to them using dot notation or bracket notation. For example, to change the`occupation`property of the`person`object to "Designer", we can use the following code:

```javascript
javascript
person.occupation = "Designer";
console.log(person.occupation); // Output: "Designer"
```

#### **Example Code**

Here's an example code that demonstrates the creation, accessing, and modification of object properties:

```javascript
javascript// Create an object representing a person
const person = {
  name: "John",
  age: 30,
  occupation: "Developer"
};

// Access the name property using dot notation
console.log(person.name); // Output: "John"

// Access the age property using bracket notation
console.log(person["age"]); // Output: 30

// Modify the occupation property
person.occupation = "Designer";
console.log(person.occupation); // Output: "Designer"
```

In conclusion, objects are a powerful and versatile data structure in JavaScript that allow us to represent complex data and functionality in a simple and organized way.