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Beto Muniz
Beto Muniz

Posted on • Edited on • Originally published at betomuniz.com

Map and Set in JavaScript for Humans

Would you like to hear more about Set and Map objects in JavaScript?

Let's catch up with them on this thread 🧵


Set in JavaScript 👇

📌 It's not key/value like the Object type. Keys are just values exposed

📌 Don't accept duplicated values

📌 It's iterable with forEarch method and for...of

📌 Conceptually is similar to []

💡 Set is useful to remove duplicates on [].


Map in JavaScript 👇

📌 Allow/preserve any key type. Even objects

📌 Don't expose insecure data properties

📌 Iterate with forEarch method and for...of

📌 Stay the insertion order doesn't matter the type

💡 Prefer Map instead of {} for client-side data manipulation.


Thoughts on Map, Set, {}, and [] in JavaScript 👇

📌 Each has a specific usage in JS

📌 Use {} for data traffic from the server.

📌 Set helps apply omit, diff, etc. on []

📌 Map return size. {} don't return size

🗣 There's not a silver bullet. Use them carefully.


😉 Hope that you now understand better such useful objects on JavaScript, they are highly valuable, and master them will make you a better JavaScript Developer.

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