Object Definitions in JavaScript

What is an Object?

• An object in JavaScript is a collection of key-value pairs.

• Keys are called properties.

• Values can be any data type including other objects or functions (called methods).

How to Define Objects

1. Using Object Literals (most common)

const person = {  name: "John",  age: 30,  greet: function() {    console.log("Hello, " + this.name);  }};

2. Using the new Object() Syntax

const person = new Object();person.name = "John";person.age = 30;person.greet = function() {  console.log("Hello, " + this.name);};

3. Using a Constructor Function

function Person(name, age) {  this.name = name;  this.age = age;  this.greet = function() {    console.log("Hello, " + this.name);  };}const person1 = new Person("John", 30);

4. Using ES6 Classes (syntactic sugar over constructor functions)

class Person {  constructor(name, age) {    this.name = name;    this.age = age;  }    greet() {    console.log("Hello, " + this.name);  }}const person1 = new Person("John", 30);

Accessing Object Properties

console.log(person.name);      // Dot notationconsole.log(person["age"]);    // Bracket notation

Adding or Modifying Properties

person.city = "New York";person["country"] = "USA";

Summary

Need help with specific object patterns or advanced object concepts like prototypes?