Differences are the inverse of intersections. They consist of all of the values that are not in every collection. If you add together the intersection and the difference, you get all of the collection values.
Sets have a subtract() method, which can be used to find the difference between two sets. Here's an example:
const mySet1 = Set.of('first', 'second', 'third');
const mySet2 = Set.of('first', 'second');
const myDiff1 = mySet1.subtract(mySet2);
const myDiff2 = mySet2.subtract(mySet1);
console.log('mySet1', mySet1.toJS());
// -> mySet1 [ 'first', 'second', 'third' ]
console.log('mySet2', mySet2.toJS());
// -> mySet2 [ 'first', 'second' ]
console.log('myDiff1', myDiff1.toJS());
// -> myDiff1 [ 'third' ]
console.log('myDiff2', myDiff2.toJS());
// -> myDiff2 []This method subtracts the set argument from the set on which the subtract() method is called. In myDiff1, you can see that the 'first' and 'second' values are the intersecting values...