objects in JavaScript

🧠 Objects in JavaScript — A Simple and Complete Guide

After understanding functions as workers, the next important concept is objects.

If functions are workers, then:

Objects are like real-world things that store data and behavior together.

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🌱 What is an Object? (First Principle)

An object is like a person or thing that has:

• properties (data)
• actions (functions)

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🧒 Real-Life Analogy

Think of a tea shop owner:

• Name → Arun
• Age → 25
• Job → Making tea

And he can:

• make tea
• take orders

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👉 That is exactly what an object is.

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⚙️ Basic Definition

An object is a collection of key-value pairs, where values can be data or functions.

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☕ Simple Example

```javascript id="k0f8kp"
const teaShop = {
owner: "Arun",
location: "Erode",
makeTea: function() {
console.log("Tea is ready");
}
};

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👉 Here:

* `owner`, `location` → properties
* `makeTea` → function (method)

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# 📦 Accessing Object Data



```javascript id="3zv2n5"
console.log(teaShop.owner);       // Arun
teaShop.makeTea();                // Tea is ready

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🧠 Objects + Functions (Important Connection)

When a function is inside an object, it is called a method.

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```javascript id="k2p4zj"
const user = {
name: "Jegan",
greet() {
console.log("Hello " + this.name);
}
};

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👉 `this.name` refers to the object itself.

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# 🎭 The `this` Keyword

> `this` means “the current object”



```javascript id="9f4gq2"
const person = {
    name: "Arun",
    speak() {
        console.log(this.name);
    }
};

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✔ this = person object

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🧾 Creating Objects (Different Ways)

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1. Object Literal (Most Common)

```javascript id="3xvmbu"
const car = {
brand: "Toyota",
start() {
console.log("Car started");
}
};

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## 2. Constructor Function



```javascript id="0m9z1p"
function Car(brand) {
    this.brand = brand;
}

const c1 = new Car("Honda");

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3. Using class (Modern Way)

```javascript id="p5yd4o"
class Car {
constructor(brand) {
this.brand = brand;
}
}

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# 🔁 Objects are Dynamic

You can add or change properties anytime.



```javascript id="0z9xxf"
const user = {};

user.name = "Jegan";
user.age = 22;

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🧠 Objects are Reference Types

```javascript id="mbg1tx"
const a = { name: "A" };
const b = a;

b.name = "B";

console.log(a.name); // B

👉 Both point to the same object in memory.

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# 🧪 Useful Object Methods

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## Object.keys()



```javascript id="y4whbq"
Object.keys(teaShop);

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Object.values()

```javascript id="y5o0o1"
Object.values(teaShop);

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## Object.entries()



```javascript id="8tvjv2"
Object.entries(teaShop);

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🌍 Real-World Example

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User Object (CRM App)

```javascript id="mtu3kk"
const user = {
id: 1,
name: "Jegan",
email: "[e-mail]",
login() {
console.log("User logged in");
}
};

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## Transaction Object



```javascript id="4k2b7x"
const transaction = {
    amount: 5000,
    type: "expense",
    category: "rent"
};

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🔗 Objects + Functions Together

Objects store data
Functions operate on data

Together, they build applications.

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🧠 Final Understanding

An object is a real-world entity in your program that groups related data and behavior together.

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🧒 Simple Definition (Child Level)

An object is like a person or thing that has information and can do actions.

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🚀 Conclusion

Objects help you:

• Organize data
• Represent real-world things
• Build structured applications

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👉 In short:

Objects are containers of data and behavior in JavaScript.

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If functions are workers,
then objects are people or things those workers belong to.

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