? JavaScript Objects – A Complete Introduction

In JavaScript, objects are collections of key-value pairs, used to store structured data and functionality. They are the building blocks of almost everything in JS.

? Creating an Object

? Using Object Literal (most common)

let person = {  name: "Alice",  age: 25,  isStudent: false};

? Using new Object()

let person = new Object();person.name = "Alice";person.age = 25;

? Object Syntax

let objectName = {  key1: value1,  key2: value2,  ...};

• Keys are also called properties

• Values can be strings, numbers, arrays, functions, or other objects

? Accessing Object Properties

Dot Notation:

console.log(person.name); // "Alice"

Bracket Notation:

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

?? Adding / Updating Properties

person.country = "USA"; // addperson.age = 26;        // update

? Deleting Properties

delete person.isStudent;

? Methods in Objects

You can define functions inside objects — these are called methods:

let person = {  name: "Alice",  greet: function() {    return "Hi, I'm " + this.name;  }};console.log(person.greet()); // Hi, I'm Alice

? Loop Through Object

for (let key in person) {  console.log(key + ": " + person[key]);}

?? Built-in Object Methods

• Object.keys(obj) – array of property names

• Object.values(obj) – array of property values

• Object.entries(obj) – array of [key, value] pairs

• hasOwnProperty() – check if object has a specific property

? Example Summary

let car = {  brand: "Toyota",  model: "Corolla",  year: 2020,  fullDetails: function() {    return `${this.brand} ${this.model} (${this.year})`;  }};console.log(car.fullDetails()); // "Toyota Corolla (2020)"

? Objects Are Everywhere

In JS:

• Arrays are objects

• Functions are objects

• DOM elements are objects

• JSON data is made of objects

Would you like to explore how objects are used in JSON or how they compare to classes?