How to compare values and put all the common elements between the 2 arrays without duplicates values (result expected [8,12])

Question

(Code of the two arrays inserted)
https://code.sololearn.com/WrfSEjWTZMgg/?ref=app

Answer 1

It looks from your expected output that you want the intersection of the two arrays, meaning only values that are present in both arrays. This would result in an array of [8, 12, 8] of which you'd then need to remove duplicate values, which can be done converting the array to a Set. This code will do that and then convert back to an array resulting in [8, 12]

let arr3 = [...(new Set(arr1.filter(x => arr2.includes(x))))];
console.log(arr3); // outputs 8, 12

Answer 2

Set is better for non-duplicate values.
Scroll to the basic operations part.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set