Today I learned

February 19, 2021

The Set Object

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.

Greetings Marco

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