Operations between sets with JavaScript

Have you ever dealt with operations between sets in JavaScript, such as union, intersection or difference?

Here some ideas of implementation:

Union

with arrays

const union = arr1.concat(arr2);
// OR
const union = [...arr1, ...arr2];

with sets

const union = new Set([...set1, ...set2]);

Intersection

with arrays

const intersection = arr1.filter(x => arr2.includes(x));

with sets

const intersection = new Set([...set1].filter(x => set2.has(x)));

Difference (from A to B)

with arrays

const difference = arr1.filter(x => !arr2.includes(x))

with sets

const difference = new Set([...set1].filter(x => !set2.has(x)));

Symmetric Difference

with arrays

const symmetricDifference = arr1
           .filter(x => !arr2.includes(x))
           .concat(arr2.filter(x => !arr1.includes(x)))

with sets

const symmetricDifference = new Set([...set1]
           .filter(x => !set2.has(x))
           .concat([...set2].filter(x => !set1.has(x))))

Demo

Have a look at this simple Stackblitz demo to play with the examples.