🚀 Quick tips! 3 ways to get unique values from an array. 💜

In this super short article, learn how to create 3 different functions that return all of the unique values in an array.

You can watch the video version here or keep scrolling for the code snippets.

1) Filter the values 👇

const getUniqueValues = array => (
  array.filter((currentValue, index, arr) => arr.indexOf(currentValue) === index)
);

2) Using reduce 👇

const getUniqueValues = array => array.reduce(
  (accumulator, currentValue) => (
    accumulator.includes(currentValue) ? accumulator : [...accumulator, currentValue]
  ), []
);

3) Destructure a new Set 👇

const getUniqueValues = array => [...new Set(array)];

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Comments

[Honza]

It seems that the [... new Set(arr)] is way faster than the other two.

jsbench.me/xnkapa5nxq/1

[Pacharapol Withayasakpunt]

Set also reliably keep what is .add() first as well. But I never really tested [...new Set(arr)] on whether the sequence is kept.

[Niall Maher]

That's actually great to know too. Finally, my laziness is paying off. 😂

[Honza]

HA! Exactly my thought on this topic 😂

[Chris Bongers]

Set is such a impressive and easy way to do this, love to use it <3