Today I learned

The Set Object

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Today I learned about the Set object. It lets you store unique values of any type, whether primitive values or oject references.

It's like a regular object, a collection of values. But the main difference is that a value in a Set may only occur once.

So if you have to manage unique data, Set objects are they right thing for you!

Here is a quick example:

const names = ['Sabrina', 'Tereza', 'Tom', 'Paul', 'Sabrina', 'Tom']
const nameSet = new Set(names)

console.log(nameSet) // ['Sabrina', 'Tereza', 'Tom', 'Paul']

If you turn any data structure into a Set, it automatically filters out the duplicates. I find this really useful.

The same goes for when you want to add a value, which is already present in your Set.

const names = ['Sabrina', 'Tereza', 'Tom', 'Paul']
const nameSet = new Set(names)

nameSet.add('Sabrina')

console.log(nameSet) // ['Sabrina', 'Tereza', 'Tom', 'Paul']

The Set prevents that values are added, which are already part of the object.

There is a lot more cool stuff you can do with sets, check out the Set Object mdn page Opens in new tab.


I hope you enjoyed this post and learned something new. If you have any questions, feel free to reach out to me on Twitter Opens in new tab or via Email Opens in new tab.

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I wish you a wonderful day! Marco