Objects in Node.js

Master JavaScript objects: creation, access, mutation, traversal, comparison, cloning, destructuring, and real-world usage.

Introduction to Objects

Objects are collections of key-value pairs used to group related data and behavior together.

1. What is an Object?

Key-value data structure.

Creating Objects

JavaScript allows object creation using literals, constructors, and factory functions.

1. Object Literal

Most common and recommended.

2. Object Constructor

Using new Object().

Accessing & Updating Properties

Object properties can be accessed using dot or bracket notation.

1. Dot Notation

Access using dot.

2. Bracket Notation

Access using strings.

3. Updating Properties

Modify existing values.

Adding & Deleting Properties

Objects can grow or shrink dynamically.

1. Adding Properties

Add new key-value pair.

2. Deleting Properties

Remove a key.

Traversing Objects

Objects are traversed using Object utilities.

1. for...in Loop

Iterate keys.

2. Object.entries

Key-value pairs.

Comparing Objects

Objects are compared by reference, not by value.

1. Reference Comparison

=== checks memory reference.

2. Value Comparison using JSON

Simple deep comparison.

Cloning Objects

Cloning prevents accidental mutations.

1. Shallow Clone

Using spread operator.

2. Deep Clone

Using structuredClone.

Object Destructuring

Destructuring allows concise extraction of properties.

1. Basic Destructuring

Extract values.

2. Renaming Properties

Alias keys.