An intersection is part of two or more collections that are the same. Immutable.js sets have built-in capabilities for finding intersections.
Let's start by creating two sets:
const myFirstSet = Set.of(1, 2, 3, 4, 5, 6); const mySecondSet = Set.of(2, 4, 6, 8, 10);
The intersection between these two sets are the values 2, 4, and 6—they exist in both collections. Sets have an intersect() method that will find this intersection for you, as follows:
const myIntersection = myFirstSet.intersect(mySecondSet);
console.log('myFirstSet', myFirstSet.toJS());
// -> myFirstSet [ 1, 2, 3, 4, 5, 6 ]
console.log('mySecondSet', mySecondSet.toJS());
// -> mySecondSet [ 2, 4, 6, 8, 10 ]
console.log('myIntersection', myIntersection.toJS());
// -> myIntersection [ 6, 2, 4 ]The values in myIntersection look good, but they appear to be out of order. This is because the iteration order of sets isn't defined.