Set in Node.js

Complete guide to JavaScript Set: creation, uniqueness behavior, adding and removing values, existence checks, size, traversal, conversion, merging, and common use-cases.

Set Basics

Set is a built-in JavaScript data structure that stores unique values. Duplicate values are automatically ignored.

1. Creating an Empty Set

Use the Set constructor.

2. Creating a Set with Initial Values

Pass an iterable to the constructor.

Basic Set Operations

Set provides methods to manage unique values efficiently.

1. Adding Values to a Set

Use add(value).

2. Checking if a Value Exists

Use has(value).

3. Removing a Value

Use delete(value).

4. Clearing the Set

Use clear().

5. Getting Set Size

Use the size property.

Traversing a Set

Set preserves insertion order and supports multiple traversal methods.

1. Traversing using for...of

Iterate over values.

2. Traversing using forEach

Callback-based traversal.

Converting Set

Conversion allows interoperability with array APIs.

1. Converting Set to Array

Use spread operator.

2. Converting Array to Set

Use Set constructor.

Set Operations

Set operations are commonly used in data processing, filtering, and comparison tasks.

1. Union of Two Sets

Combine all unique elements from both sets.

2. Intersection of Two Sets

Find common elements between two sets.

Set Fundamentals Using Map

A Set can be conceptually represented using a Map where values are stored as keys and the map values are ignored. This explains why Set supports fast existence checks.

1. Simulating a Set Using Map

Store values as map keys.

2. Why Set Exists if Map Can Do This?

Conceptual difference.