JavaScript Objects #

An object is a collection of key-value pairs. In JavaScript, objects are used to represent complex data structures and are a fundamental part of the language.

Creating Objects #

You can create an object using object literal syntax {} or the Object constructor.

// Object literal
let person = {
 firstName: "John",
 lastName: "Doe",
 age: 30
};
console.log(person);
// Object constructor
let car = new Object();
car.make = "Toyota";
car.model = "Camry";
console.log(car);

Accessing Properties #

You can access object properties using dot notation or bracket notation.

let person = {
 firstName: "John",
 lastName: "Doe"
};
// Dot notation
console.log(person.firstName); // "John"
// Bracket notation
console.log(person["lastName"]); // "Doe"

Object Methods #

An object can have methods, which are functions stored as object properties.

let person = {
 firstName: "John",
 lastName: "Doe",
 greet: function() {
 console.log(`Hello, my name is ${this.firstName} ${this.lastName}`);
 }
};
person.greet(); // "Hello, my name is John Doe"

The this Keyword #

In an object method, this refers to the object itself. The value of this can change depending on how the function is called.

Object Destructuring #

Destructuring makes it easy to extract properties from objects.

let person = {
 firstName: "John",
 lastName: "Doe",
 age: 30
};
const { firstName, age } = person;
console.log(firstName); // "John"
console.log(age); // 30