Understanding the Best Use of new Set() in JavaScript

Discover the most effective way to utilize `new Set()` in JavaScript for filtering duplicates from an array. Learn why using spread syntax is often the better choice.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Which one is a better use of new Set() in JavaScript?

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the Best Use of new Set() in JavaScript

When working with arrays in JavaScript, one common challenge developers face is the presence of duplicate values. To tackle this, many turn to the Set object, which is designed to store unique values. However, there are multiple ways to implement a Set and not all of them are equally effective. In this article, we'll explore the differences between two popular methods for utilizing new Set() and determine which approach is the best for filtering duplicate values from an array.

The Problem: Duplicates in Arrays

Imagine you have an array with several duplicate entries, like this:

[[See Video to Reveal this Text or Code Snippet]]

Our goal is to create a new array that contains only unique values. The good news is that JavaScript's Set object can help us achieve this. However, how we implement it can impact our results and functionality. Let's look at two common methods for filtering duplicates.

Comparing Two Methods

Method 1: Using Spread Syntax with Set

The first method involves creating a new Set and then spreading its values into an array. Here’s how it looks:

[[See Video to Reveal this Text or Code Snippet]]

While this does produce a unique set of values, it's essential to note how the values are stored. The filteredArray1 here is actually a Set, not an array.

Method 2: Array from Set

The second method simplifies the process by taking the array directly from the Set like this:

[[See Video to Reveal this Text or Code Snippet]]

This method directly utilizes the Set to create a new array, thus ensuring that filteredArray2 is indeed an array containing unique values.

Why Method 2 is Superior

Type of Variable

One critical distinction between the two methods is the type of the resulting variable:

First Method: filteredArray1 is a Set, which may not be the desired type for subsequent operations.

Second Method: filteredArray2 is guaranteed to be an array, allowing for easier manipulation and compatibility with other array methods (e.g., map(), filter(), reduce()).

Readability and Clarity

Using spread syntax in the second method not only ensures an array is returned, but it also enhances code readability. It clearly conveys the intent to create an array of unique values, making the code easier for other developers to understand.

Conclusion

By comparing both methods of using new Set() in JavaScript, it's clear that the second method—using spread syntax to produce an array—is the optimal choice for filtering duplicates. This strategy not only guarantees the correct data type but also improves code readability and intent clarity.

So the next time you find yourself needing to remove duplicates from an array, remember to use this efficient approach. Happy coding!