Newsletter - Feb 2024 #1

7 new Set methods in JavaScript: union(), intersection(), +5 more

Guess the output!

The new Set union() method gives us all the unique items in both sets.

And since it's immutable and returns a copy, you can chain it indefinitely:

What elements are in both sets?

JavaScript Mutation Observer.

An underrated API for watching for changes in the DOM: "child added", "attribute changed", and more.

I see a bunch of people online curious to know the point of this API in the real-world.

In this post I'll show you how I used it to easily shut-up this annoying script carrying out unwanted activities on the page.

And you'll see how sleek and polished the UI elements became after this.

Of course <br/> is what we all grew up with from our HTML beginnings, but there's more.

Like... CSS white-space: pre-wrap: