x/30_seconds_of_typescript/docs/union.md
Returns every element that exists in any of the two arrays once.
Create a Set with all values of a and b and convert to an array.
Set
a
b
const union = (a: any[], b: any[]) => Array.from(new Set([...a, ...b]));
union([1, 2, 3], [4, 3, 2]); // [1, 2, 3, 4]