Sets versus WeakSets

Now, we understand the fundamental meaning of weak in the term WeakMap or WeakSet. It is not very complex to predict how sets work and how WeakSet differs from them. Let's take a quick look at the functional difference and then move on to the API.

Understanding WeakSets

WeakSet is very similar to WeakMap; the values that a WeakSet can hold are only objects and cannot be primitives just like in the case of a WeakMap. The WeakSets are also not enumerable, so you do not have direct access to the values available inside the set.

Let's create a small example and understand the difference between a Set and a WeakSet: 

var set = new Set();
var wset = new WeakSet();

(function() {

  var a = {a: 1};
  var b = {b: 2};
  var c = {c: 3};
  var d = {d: 4};

  set.add(1).add(2).add(3).add(4);
  wset.add(a).add(b).add(b).add(d);

})();

console.dir(set);
console.dir(wset);

One important thing to note is that WeakSet does not accept primitives and can only accept objects similar to the...