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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