Arrays and Objects

So far, we've stored one piece of data in one variable (like let fruit = "apple"). But what if you have a list of 100 fruits? Or what if you want to store a "User Profile" with a name, age, and email?

This is where Arrays and Objects come in.

1. Arrays (The Ordered List)

An Array is a single variable that holds a list of items in a specific order. You define an array using square brackets [].

let fruits = ["Apple", "Banana", "Cherry"];

Accessing Items (Indexing)

In programming, we start counting at 0.

• fruits[0] is "Apple"
• fruits[1] is "Banana"

Common Array Actions:

fruits.push("Orange"); // Adds to the end
fruits.pop();         // Removes the last item
console.log(fruits.length); // Tells you how many items are inside (3)

2. Objects (The Labeled Cabinet)

While Arrays are lists, Objects store data in "Key-Value" pairs. Use curly braces {} for objects. They are perfect for describing a single thing in detail.

const user = {
    firstName: "Ajay",
    lastName: "Dhangar",
    age: 25,
    isDeveloper: true
};

Accessing Data:

You use Dot Notation to get information out of an object:

console.log(user.firstName); // Output: Ajay
console.log(user.age);       // Output: 25

3. Which one should I use?

It can be confusing at first. Use this simple rule:

Use an Array when...	Use an Object when...
You have a list of similar things.	You want to describe one thing.
Order matters (1st, 2nd, 3rd).	Order doesn't matter.
Example: A list of students.	Example: A single student's profile.

4. Combining Both (The Real World)

In a real application like CodeHarborHub, we often have an Array of Objects. This is how a list of tutorials or users is actually stored!

const courses = [
    { title: "HTML Basics", status: "Completed" },
    { title: "CSS Mastery", status: "In Progress" },
    { title: "JS Logic", status: "Not Started" }
];

// To get the title of the first course:
console.log(courses[0].title); // Output: HTML Basics

Practice: The "My Team" List

Try building this in your script.js:

1. Create an Object for yourself called me with your name and favorite hobby.
2. Create an Array called myTeam and put your object inside it.
3. Add another object to the array for a friend.
4. Use console.log to print the hobby of the second person in your array.

const me = { name: "Ajay", hobby: "Cricket" };
const friend = { name: "Rahul", hobby: "Coding" };

const myTeam = [me, friend];

console.log(myTeam[1].hobby); // Output: Coding

Const with Arrays/Objects

You'll notice we usually use const for Arrays and Objects. This is because even though the content inside might change (we add a fruit or update an age), the "cabinet" itself stays the same.